Liability Structure in Small-Scale Finance: Evidence from a Natural Experiment Fenella Carpena, Shawn Cole, Jeremy Shapiro, and Bilal Zia Microfinance, the provision of small individual and business loans, has experienced dramatic growth, reaching over 150 million borrowers worldwide. Much of the success of microfinance has been attributed to attempts to overcome the challenges of information asymmetries in uncollateralized lending. However, very little is known about the optimal contract structure of these loans, and there is substantial variation across lenders, even within a particular setting. This paper exploits a plausibly exogenous change in the liability structure offered by a microfinance program in India, which shifted from individual to group liability lending. We find evidence that the lending model matters: for the same borrower, the required monthly loan installments are 11 percent less likely to be missed under the group liability setting in comparison with individual liability. In addition, compulsory savings deposits are 20 percent less likely to be missed under group liability contracts. JEL codes: D14, O12, O16, O17 Theory and evidence highlight financial market imperfections as a central cause of poverty and a key impediment to growth (Banerjee and Newman, 1993; Rajan and Zingales, 1998). In theories of capital accumulation, for example, financial market imperfections influence the ability of the poor to borrow for investments in education and physical capital. Additionally, in models that explain entrepreneurship, information asymmetries and transaction costs prevent the poor from undertaking profitable entrepreneurial activities because they often have no collateral. The lack of access to financial services Fenella Carpena is a PhD student in the Department of Economics at the University of California, Berkeley; her email address is fenella@econ.berkeley.edu. Shawn Cole is an Associate Professor of Business Administration at Harvard Business School; his email address is scole@hbs.edu. Jeremy Shapiro is a Consultant at McKinsey & Company; his email address is jeremypshapiro@gmail.com. Bilal Zia (corresponding author) is an Economist in the Development Research Group at the World Bank; his email address is bzia@worldbank.org. This project is a collaborative research effort with Saath Microfinance. The authors thank Saath, Xavier Gine ´ , David McKenzie, Petia Topalova, and workshop participants at the World Bank for helpful comments and suggestions. Stuti Tripathi and the Center for Microfinance at IFMR provided excellent research assistance. This work was supported by the World Bank Gender Action Plan, the HBS Division of Faculty Research and Development to S.C., and the NSF Graduate Research Fellowship Program to F.C. THE WORLD BANK ECONOMIC REVIEW, VOL. 27, NO. 3, pp. 437 –469 doi:10.1093/wber/lhs031 Advance Access Publication December 4, 2012 # The Author 2012. Published by Oxford University Press on behalf of the International Bank for Reconstruction and Development / THE WORLD BANK. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com 437 438 THE WORLD BANK ECONOMIC REVIEW may thus leave many productive opportunities for the poor untapped and may generate persistent income inequality and low growth (Beck et al., 2007).1 Microfinance, which is the provision of credit, savings, and other financial services to low-income households and entrepreneurs, has exploded in popular- ity and coverage in recent years, particularly in its ability to meet the large unmet demand for finance (Morduch, 1999; Armenda ´ riz de Aghion and Morduch, 2010). Both emerging markets and developed economies, including the United States, now provide microfinance services through a variety of public and private channels. The growth of microfinance has been unprecedent- ed: between 2004 and 2008, the sector’s average annual asset growth rate was 39 percent, reaching US$60 billion in total assets by the end of 2008 (Chen et al., 2010). A careful evaluation of microfinance in Banerjee et al. (2009) reveals that microcredit has important effects on business outcomes and the composition of household expenditures. The rapid growth of microfinance and its potential for promoting development have attracted the interest not only of governments, donors, and socially oriented investors but also of mainstream commercial banks. Perhaps the most celebrated feature of microfinance is the group liability contract, which is a lending methodology pioneered by the Grameen Bank in Bangladesh. Under this contract, loans without collateral are extended to a group of borrowers whose members are jointly liable for each other’s repay- ment. Because groups form voluntarily and group members are responsible for paying off each other’s debts, borrowers have the incentive to screen for risky clients, monitor their peers, and enforce repayment. The success of this model with the Grameen Bank led to its replication in many countries around the world, reaching more than 150 million individuals by the end of 2007 (Daley-Harris, 2009). This model is particularly important because small firms suffer the most from institutional weakness (Beck et al., 2005) and because the structure of the banking sector may have important distributional impacts on growth (Cetorelli and Gambera, 2001). Although most microfinance organizations use group liability, not all do so. On the one hand, group liability may solve information asymmetry problems by leveraging social ties and the borrower’s knowledge about the community, and it may reduce monitoring costs to the lender by motivating borrowers to monitor each other. On the other hand, social sanctions may be limited, bad clients may free-ride on good clients, and borrower groups may collude against the lender. In addition to group liability lending, many microfinance programs employ a variety of approaches to maintain high repayment rates. For example, some programs implement frequent repayment schedules and progressive lending, or they require collateral substitutes. However, very little is known about the efficiency of these designs in ensuring repayment. 1. See World Bank (2008) for a literature summary. Carpena, Cole, Shapiro, and Zia 439 The question of an optimal loan contract structure remains largely unan- swered in both the theoretical and the empirical microfinance literature. Theoretical studies have primarily focused on explaining how and why the group liability mechanism works and offering competing predictions on its benefits, whereas the empirical literature lags behind the theory. Two impor- tant exceptions are Gine ´ and Karlan (2009) and Attanasio et al. (2011). Gine ´ and Karlan (2009) report on a field experiment in the Philippines to test the effect of individual versus group liability lending. Their analysis focuses on the importance of peer monitoring and finds no significant difference in default among individual and group borrowers. Gine ´ and Karlan identify the effects of peer monitoring, but they do not focus on the effects of joint liability. In con- trast, our paper examines the effect of the contract structure on the group of borrowers who are willing to borrow with either individual or group liability. Attanasio et al. (2011) conducted a field experiment in Mongolia in which vil- lages were randomly assigned to obtain access to group loans, individual loans, or no loans. The main objective of Attanasio et al. (2011) is to measure the impact of both types of microcredit on different poverty measures. The authors find a positive impact for group liability loans on food consumption and entre- preneurship, with no difference in repayment rates between individual and group liability. The identification of the impact of group liability on outcomes such as the default rate is complicated by the standard problems of selection and omitted variable bias. Individuals with different financial habits might choose one form of contract but not the other. Alternatively, lenders with different levels of sophistication may attract different client mixes and offer different contracts. One cannot simply compare clients across lending contracts because self- selection or other aspects of the program may be the cause of any observed differences. In this paper, we use a natural experiment to compare loan repayment and savings discipline between individual and group lending models.2 In this setting, group lending differs from individual lending in both the liability struc- ture and the repayment practices. In group lending, borrowers are liable for the scheduled payments of group members, and the loan officer interacts primarily with the group leader, who collects payments from the other group members. Under individual lending, the borrowers are personally liable and interact directly with the loan officer. Our empirical strategy takes advantage of a change in the lending policies of Saath, a non-government organization provid- ing microfinance services in India. Saath switched from individual to group lending. This transition was governed by a strict policy rule: after a particular date, all of the borrowers completing an individual liability cycle were offered a group liability loan in their next loan cycle. The individual liability loan com- pletion dates were distributed relatively uniformly throughout the year, offering 2. Throughout this paper, we use the terms “group liability” and “joint liability” interchangeably. 440 THE WORLD BANK ECONOMIC REVIEW a natural variation in the timing of the loan contract transitions. Thus, in July, for example, individual liability borrowers completing a loan cycle would switch to group liability in the following loan, whereas those whose loan cycle ended after July would remain under an individual contract setting until the end of their cycle. This plausibly exogenous change, which was phased in over time, generates natural control groups and allows us to credibly identify the causal impact of the group liability structure in what amounts to a repeated difference-in-difference framework. At any particular point in time, our “treat- ment” group consists of clients who have fully repaid their individual liability loan and who currently have a group liability loan, whereas our “control” group consists of individual liability loan clients who will eventually convert to a group liability loan. Our primary analysis focuses on loan performance and estimates the effect of group liability on these outcomes. We find that the group liability structure significantly improves repayment rates. In particular, clients are approximately 11 percent less likely to miss a monthly repayment in the group liability setting relative to individual liability; this effect holds even with individual fixed effects. We also find that there is greater discipline regarding the monthly com- pulsory savings deposits when clients have a group liability loan. Specifically, compulsory deposits are approximately 20 percent less likely to be missed in the group liability setting. Our results provide the first credible evidence that group liability contracts improve upon individual liability, particularly in en- suring repayment and increasing savings discipline among clients. These results, however, are subject to some important caveats. First, the transition to group liability lending was accompanied by other changes to the lending structure, particularly an increase in the loan size, which may have raised the continuation value of borrowing. Nevertheless, we argue that our es- timates of the impact of these changes in the lending model should be in the lower bounds. Second, because our empirical strategy focuses on clients who chose to borrow under both individual and group liability settings, the external validity of our results may be limited. Third, limitations in the data availability preclude us from examining loan outcomes such as delinquency or prepayment. Finally, our empirical strategy does not allow us to test for the specific mecha- nisms by which group lending improves repayment. Based on our discussions with Saath, interviews of field officers, and our reading of the evidence, we speculate that “peer pressure” is the mechanism at work. We discuss these caveats further in Section IV. From a practical and policy perspective, our results are quite timely. Microlenders worldwide are increasingly weakening joint liability in their lending approaches (Armenda ´ riz de Aghion and Morduch, 2010). BancoSol in Bolivia has shifted a significant proportion of its lending portfolio from group to individual lending, and even the Grameen Bank has moderated its joint lia- bility clause, allowing defaulters to get back on track without invoking group pressure. Therefore, our results suggest a cautionary tale for microfinance. Carpena, Cole, Shapiro, and Zia 441 Many MFIs are moving away from joint liability to individual liability, but this transition is not supported by strong empirical evidence. This finding is impor- tant because, to our knowledge, only two other papers examine the relative merits of joint and individual liability contracts. Our paper underscores the fact that more research is required to provide better policy guidance for MFI practitioners worldwide. The rest of this paper is organized as follows. Section I reviews the existing literature on the liability structure in microfinance. Section II provides the back- ground for the microfinance program that we study and explains the change in the liability structure of its loan products. In Section III, we provide a descrip- tion of the data and summary statistics. We discuss our empirical strategy and results in Section IV. Finally, Section V concludes the paper. I. PREDICTIONS OF GROUP LIABILITY A wealth of theoretical literature in microfinance explores the mechanisms behind group liability contracts, particularly in terms of how they mitigate in- formation asymmetries and enforcement problems. Stiglitz (1990) shows that the group liability structure overcomes ex ante moral hazard because it creates incentives for group members to monitor each other’s loans. Similarly, Banerjee et al. (1994) study credit cooperatives and underscore the role of peer monitoring. These authors describe a model in which higher monitoring results in higher borrower effort and, hence, a higher probability of project success. Even if a project succeeds, however, borrowers may refuse to repay or may claim that the project failed so that they can avoid repayment. This type of strategic default is captured in several theoretical studies on group liability. For example, Besley and Coate (1995) provide a model demonstrating that joint lia- bility may harness social capital to increase a borrower’s willingness to repay. Likewise, Armenda ´ riz de Aghion (1999) demonstrates that joint liability agree- ments may reduce the incidence of strategic default because borrowers may impose social sanctions on the defaulter. In addition to examining moral hazard, the theoretical literature investigates how joint liability mitigates adverse selection. Ghatak (2000) describes a model in a scenario in which borrowers have ex-ante information about the riskiness of other borrowers’ investment projects, but lenders do not. Joint lia- bility thus acts as a screening device that induces “assortative matching.” Specifically, borrowers with safe investments partner with other safe borrowers, leaving risky borrowers to form groups among themselves. These theoretical models, among others, have shown that group liability may improve repayment rates by alleviating imperfections in the credit market. However, whether group liability outperforms other contract structures remains an open question in the microfinance literature. For example, Besley and Coate (1995) point out in their model that if borrowers cannot repay as a group, then some group members will not find it worthwhile to contribute 442 THE WORLD BANK ECONOMIC REVIEW their share of repayment even though they would have repaid under individual lending. Inconclusive empirical evidence accompanies these ambiguous theoretical predictions. Some empirical studies support the theoretical advantages of group liability. For instance, in Bangladesh, Sharma and Zeller (1997) show that groups that were formed through self-selection had better repayment rates; however, this study may suffer from omitted variable biases. Other studies provide little empirical support for this theory. For example, Ahlin and Townsend (2007) use Thai data to show that repayment rates are negatively as- sociated with social ties. Only a handful of studies examine the merits of group liability relative to other contract structures. Fischer (2010) conducts a series of lab experiments with actual microfinance clients and provides evidence that the contract struc- ture affects project selection. Specifically, he finds that group liability increases risk-taking relative to individual liability contracts because borrowers free-ride on the insurance provided by their partners. In a randomized experiment in India in which borrowers were assigned to either weekly or monthly repayment meetings, Feigenberg et al. (2010) find that more frequent repayment meetings build social capital among borrowers, which, in turn, leads to reduced default. The most relevant studies on repayment rates under different loan liability structures are Gine ´ and Karlan (2009) and Attanasio et al. (2011). Gine ´ and Karlan (2009) report evidence from two field experiments in the Philippines. In the first experiment, borrowers who had signed up under a group liability structure were converted to individual liability. Because both the joint and indi- vidual liability groups previously underwent the same screening, the authors can independently identify the peer monitoring effect under group liability. However, they cannot identify or rule out any impact of screening with this methodology. In addition, the group repayment and monitoring mechanisms may be entrenched and difficult to undo, even with an individual liability struc- ture. Their second experiment randomly introduced either group or individual liability lending to new borrowers. However, the experiment was conducted at the loan center level, and take-up was quite uneven between the group and in- dividual loan centers, resulting in potential statistical power concerns. In both instances, the authors find that the default rates are invariant to the contract structure. Attanasio et al. (2011) conduct a field experiment in Mongolia where villag- es were randomly assigned to group loans, individual loans, or no loans. The authors seek to measure the impact of individual and group loans on reducing poverty. In particular, the study finds that clients who received group loans had higher food consumption and were more likely to operate a business than clients in the control villages. Clients in the individual-lending villages had no significant increases on any of these measures. For the repayment outcomes, the authors find no significant differences in the repayment rates between indi- vidual and group liability. Carpena, Cole, Shapiro, and Zia 443 Although loan default and repayment are the primary outcomes of interest when examining group liability contracts, the economics literature on rotating savings and credit organizations (Roscas) suggests that group liability may have positive effects on savings. Bouman (1995) argues that participating in credit and savings groups allows individuals to avoid demands for financial support from their relatives because contributions to a Rosca are generally recognized by society as senior claims. In a theoretical model, Ambec and Treich (2007) show that Roscas can serve as a commitment device that helps people to over- come self-control problems. Gugerty (2007) provides support for this model, reporting that many Rosca participants in rural Kenya cite “you can’t save alone” or “sitting with other members helps you to save” as their primary mo- tivation for participating in a Rosca. Our paper complements Gine ´ and Karlan (2009) by examining the optimal contract structure in an alternative setting. Although the original experiment in Gine´ and Karlan (2009) focuses on moving from group to individual liability contracts, we explore the reverse; that is, we explore the shift from individual to group liability. The following section describes the setting and our empirical strategy in more detail. II. EMPIRICAL SETTING Our partner institution, Saath, is a non-government organization based in Ahmedabad, India. Founded in 1989, Saath implements development initiatives in slum communities, including health, infrastructure improvement, and liveli- hood training programs. Additionally, Saath provides credit and savings servic- es to the urban poor through its microfinance unit. In 2009, Saath Microfinance had over 6,400 active clients in 4 branches with a savings portfo- lio of INR 18 million (USD 390,000) and a loan portfolio of INR 19 million (USD 410,000).3 Although Saath has provided mentoring support to community-based credit and savings groups since the mid-1990s, its microfinance unit was not formally established until 2002. In that year, Saath integrated these credit and savings groups into its organization and registered them as cooperative societies with the Indian government. Saath also began managing these credit and savings co- operatives at this time, evolving into the Saath Microfinance Unit. Today, Saath Microfinance provides various financial services to slum communities, in- cluding voluntary savings accounts, compulsory savings accounts, and group li- ability loans. Savings Products Since its inception in 2002, Saath Microfinance has offeredvoluntary savings accounts to its clients. These voluntary savings accounts earn an interest rate of 3. Based on Saath’s 2008–2009 Annual Report. 444 THE WORLD BANK ECONOMIC REVIEW 6 percent per year and do not require a minimum balance. As the name sug- gests, members are not obliged to make regular deposits into voluntary savings accounts. Any amount can be deposited, but only six withdrawals can be made per year. In November 2007, Saath Microfinance initiated compulsory savings ac- counts for its members. Specifically, members are required to deposit INR 100 (USD 2) every month into compulsory savings accounts for the duration of their membership with Saath Microfinance. Clients may withdraw any amount from their compulsory savings at any time as long as a minimum balance of INR 3,500 (USD 70) is maintained. Similar to voluntary savings, compulsory savings earn an interest of 6 percent per year. Any amount that the client de- posits over the compulsory savings of INR 100 is deposited into the client’s voluntary savings account. The goal of the compulsory savings account is to allow clients to build a financial buffer stock against adverse shocks and to provide low-cost capital to Saath. These compulsory deposits were mandated for all borrowers independent of the switch to group liability loans. Hence, all outstanding loans under both individual and group liability were required to make compulsory deposits after November 2007. In Section IV, we compare adherence to these compulsory deposits for the same person as she moves from individual to group liability. Loan Products In addition to savings products, Saath Microfinance provides loans for asset creation (e.g., house repairs), production (e.g., business working capital), and consumption (e.g., health, social functions). From Saath’s beginnings in 2002 until November 2007, it provided credit through individual liability loans. Beginning in November 2007, Saath discontinued its individual liability loans, instead offering group liability loans to members applying for credit. Under the individual liability loan model, a client was required to have been a member of Saath for at least six months with a savings account to be eligible for a loan. Members could borrow up to three times their savings account balance at an interest rate of 18 percent per year.4 These individual-liability loans generally require no collateral; however, each loan applicant must meet two requirements. First, the loan applicant must have two “guarantors” who also have savings accounts with Saath. Second, the combined savings balances of the loan applicant and the two guarantors must be greater than or equal to the loan amount applied for. Although the guarantors are, in principle, re- quired to maintain these savings balances throughout the duration of the loan, in practice, this rule is not strictly enforced. The guarantors are not eligible for 4. Microfinance organizations typically quote interest rates in one of two forms: “declining,” the standard used in developed markets, where the amount of interest due each period is calculated based on the interest rate and the remaining principal, and “flat,” where the interest payments are calculated using the original principal amount. Thus a 10 percent “flat” rate is significantly higher than a 10 percent “declining” rate. Saath quotes rates using the standard declining balance approach. Carpena, Cole, Shapiro, and Zia 445 a loan until the loan that they guaranteed has been fully repaid, but loan repay- ment is the sole responsibility of the borrower. The borrowers are required to make monthly installments that cover principal and interest. The monthly prin- cipal installment is a fixed amount, and because the interest rate reflects a de- clining balance, the total installment amount ( principal plus interest) varies every month. If the borrower defaults, Saath reserves the right to seize the bor- rower’s savings. If the savings are not sufficient to cover the loan, Saath re- serves the right to take the guarantor’s savings as well. However, in practice, as an NGO whose mission is to empower the poor, Saath has never seized any of its individual borrowers’ or guarantors’ savings. With the group liability model, however, Saath extends credit to groups of individuals at an interest rate of 24 percent per year. Four loan size categories are available to clients: (1) Rs. 3,000–5,000, (2) Rs. 6,000–10,000, (3) Rs. 11,000–20,000, and (4) Rs. 21,000–30,000. These groups are formed primarily through self-selection with joint applications submitted to Saath. The groups are composed of three to six individuals, all of whom must be Saath Microfinance members. Within each group, several criteria must be fulfilled. First, at least 50 percent of the group must have been Saath Microfinance members for at least 6 months and must have at least asavings account. Second, at least 50 percent of the group must be female. Third, relatives or in- dividuals from the same household are not allowed in the same group. Finally, the loan terms must be homogenous across group members; that is, the number of installments and the monthly installment due dates must be the same, and the loan amount must not vary widely within each group. As in the individual liability model, group liability borrowers are required to make monthly installment payments for both principal and interest, although in this setting, the total installment amounts ( principal plus interest) are equal every month. (In the individual liability model, the monthly principal installment re- payment is fixed, but the interest and, therefore, the installment size vary each month.) Before any loans are disbursed, the group members are also required to sign a “mutual agreement form” stating that they are liable to pay each other’s debts in the event of default or delinquency. Borrower groups who have defaulted or are delinquent are not eligible to receive another loan from Saath. The Shift from Individual to Group Liability Saath’s decision to shift from offering individual liability to group liability loans in November 2007 was driven by a change in the management’s priori- ties. Saath wanted to lend to more people, provide larger loan amounts, and expand its microfinance operations geographically, but its lending activities had become stagnant under the individual liability model. In particular, the “guarantors” requirement for individual liability loans restricted credit eligibili- ty because Saath had already reached a point where almost all of its members were either borrowers or guarantors. Additionally, savings clients were reluc- tant to stand as guarantors for other clients’ loans, and the loan amounts were 446 THE WORLD BANK ECONOMIC REVIEW limited to 3 times the total savings account balance of the borrower. Saath’s management thus shifted to group liability loans to overcome these restrictions in its individual liability model. In terms of the models discussed above, the limited ability of Saath members to pledge savings as collateral prevented Saath from expanding, and Saath saw group liability as a way to solve this problem. In the year following this change, Saath gained almost 800 new clients and in- creased its reach from 11 to 20 wards. The transition from individual liability to group liability loans was imple- mented using the following rule. Beginning in November 2007, all new loans disbursed were group liability loans; Saath would no longer disburse individual liability loans. However, existing loans whose terms lasted beyond November 2007 were unaffected. For example, individual liability loan clients who com- pleted their loan in February 2008 continued under the individual liability con- tract until then. After February 2008, if they chose to borrow again, they received a group liability loan. The date to switch from individual to group lia- bility was therefore determined by the individual liability loan completion dates. These completion dates and the subsequent conversion to group liability loans were distributed relatively uniformly throughout the year. Although Saath’s loan product moved from individual to group liability be- ginning in late 2007, the location for repayments, the frequency of loan repay- ment collection, and the salaries for the field officers remained similar across time in our dataset. An empirical concern for the subsequent analysis is whether Saath’s policy shift from individual to joint liability was accompanied by a shift in its loan collection techniques. In June 2010, we conducted short interviews with Saath field officers regarding repayment collection. We were able to interview 10 out of the 12 Saath field officers who collected repayment among the sample of clients we study; the remaining field officers are no longer with Saath. The results from this survey confirm that the location and frequen- cy of loan repayments remained the same across the two settings. Specifically, for both individual and group liability loans, we find that field officers collected repayment at the client’s household every month 100 percent of the time. Additionally, 90 percent of the time under both regimes, the lender turned down future loan requests from defaulting clients. For group liability borrowers, Saath does not require a group to designate one of its members as the “group leader.” However, in practice, all groups have a leader who is in charge of collecting repayments from the other members. Hence, for individual borrowers, the field officers visit each bor- rower, whereas for group borrowers, the field officers typically visit only the group leader’s household. If any member of a particular borrower group fails to make a scheduled payment, the field officer assembles all of the group members together and collects the installment amount from the other members, as stipulated in the group liability contract. Both individual liability borrowers and joint liability borrower groups in default are not granted future Carpena, Cole, Shapiro, and Zia 447 loans. In addition, over the period that we study, there was no change in wages among the field officers, who continued to receive a fixed monthly sum.5 In summary, borrowing conditions changed in the following ways: (1) bor- rowers were obliged to enter joint liability lending groups rather than borrow- ing independently from Saath; (2) the loan officers collected repayment from the group leader rather than from each individual borrower; (3) monthly in- stallments became fixed rather than varying; and (4) the interest rate increased from 18 percent to 24 percent. Given that multiple dimensions of the contract structure were changing, we discuss the implications of each of these changes on our analysis in Section IV. I I I . D ATA CO L L E C T I O N AND S U M M A RY S TAT I S T I C S In this study, we use data from Saath Microfinance’s administrative software systems. The loan data cover outstanding loans every month from April 2005 through March 2009. Because the change in the type of loan contract occurred in November 2007, the data contain more than two years of monthly data on individual liability loans and more than one year on group liability loans. Data are available electronically from only 2 of the 4 Saath Microfinance branches, Behrampura and Vasna; we focus on these branches. These two branches are the largest and the oldest, accounting for the vast majority of Saath’s clients. The data were maintained for accounting purposes to record cash flowing in and out of each branch. The data are therefore of very high quality. The data do not, however, contain information on the terms of each loan, such as matu- rity dates, installment amounts, and amounts outstanding. These data were re- corded by the loan officers in the client passbooks and administrative ledgers. As a result, we are unable to examine the overdue amounts, prepayments, and similar measures.6 The data on loans cover April 2005 to March 2009, but savings data were only available from January 2008 to March 2009. The savings data include the monthly aggregate deposit and withdrawal amounts for the compulsory savings accounts. 5. After March 2009, field officers received 1 percent of the loan interest they collect. Surveys of field officers indicate that they were not aware of this change in compensation structure before it occurred. Nevertheless, to isolate the focus of our study on contract structure, we exclude months after March 2009 in the analysis. 6. The loan data come from three software systems that Saath Microfinance has used at different points in time. Each of the two branches in our dataset used a separate system until early 2008, when the current system was introduced in both branches. Because client identifiers were not carried over from one software system to another, we had to rely on using client names to track individuals over time. These names were unique because they included first, middle, and last names. In identifying clients across systems, 80 percent of the clients had exact name matches, while 14 percent had to be matched by hand due to name spelling errors. The remaining 6 percent, however, could not be matched to the current software system. It is likely that these clients have withdrawn their membership with Saath Microfinance and therefore have not borrowed under the group liability setting because Saath migrated information from the previous to the current software system only for existing members. 448 THE WORLD BANK ECONOMIC REVIEW As previously described, in our main analysis, we study borrowers who re- ceived both individual and group liability loans to overcome the selection problem. Hence, in our dataset, these clients begin with an individual liability loan and, after November 2007, receive a group liability loan. In Saath’s Behrampura and Vasna locations, we identified a sample of 276 such clients, representing 22 percent of the loan client base in these two branches as of March 2009. Table 1 provides the summary statistics for our sample. Collectively, these clients received a total of 748 loans from Saath, of which 450 were individual liability loans and 298 were group liability loans. The average individual liabil- ity loan amount was approximately INR 10,000 (USD 220), and the group lia- bility loan average was approximately INR18,000 (USD 390). Figure 1 plots the number of group liability loans disbursed over time. As the figure shows, the borrowers in our sample, all of whom received individual liability loans, switched to group liability loans in varying months. Our empirical strategy takes advantage of this staggered timing to compare individual liability loan clients who received group liability loans to future recipients to identify the impact of group liability on loan repayment behavior and savings discipline. I V. E M P I R I C A L S T R A T E G Y AND AN A LY S I S Empirical Strategy To study the effect of contract structure on lending outcomes, we exploit the natural experiment provided by Saath’s change in policy. The presence of an exogenous policy change is important. Without exogenous variation, it would be very difficult to determine whether differences in outcomes were attributable to contract structure or to any number of other unobservable characteristics of either the borrowers or the lending institutions. Indeed, theory predicts that dif- ferent contracts are optimal for different types of borrowers. To overcome the selection problem, we focus our attention on the Saath bor- rowers who received both individual and group liability loans. We exploit the T A B L E 1 . Summary Statistics Individual Liability Group Liability Total No. of Total No. of No. of Ave. Loan Amt No. of Ave. Loan Amt Branch Clients Loans Loans (Rs.) Loans (Rs.) Behrampura 198 512 303 9981.1 209 19081.34 Vasna 78 236 147 9927.211 89 16764.04 Full Sample 276 748 450 9963.014 298 18389.26 Notes: This table reports the summary statistics for the borrowers in our sample. These bor- rowers received both individual liability and group liability loans. Source: Authors’ analysis based on data sources discussed in the text. Carpena, Cole, Shapiro, and Zia 449 F I G U R E 1. Group Liability Loans Disbursement in Sample Notes: This figure plots the number of group liability loans disbursed over time in our sample. All of the borrowers were individual liability borrowers who subsequently received a group liability loan after the policy change. Source: Authors’ analysis based on the data sources discussed in the text. natural phasing-in of group liability in what amounts to a repeated difference-in-difference framework. At any point in time, our “treatment” group thus consists of clients who have fully repaid their individual liability loan and who currently have a group liability loan, whereas our “control” group consists of individual liability loan clients who will eventually convert to a group liability loan. Specifically, we estimate the following equation: yilt ¼ a þ bTil þ gi þ dt þ 1ilt ð1Þ where the subscript i refers to individuals, l refers to loans, and t refers to months. T is a dummy variable equal to 1 if loan l of client i is a group liability loan and 0 if it is an individual liability loan. yilt is a measure of loan repay- ment or savings discipline. The estimate of b then provides the effect of switch- ing an individual who is already borrowing to the group liability loan. We include time effects dt because the conversion to group liability loans was stag- gered across individuals, and the individual fixed effects gi absorb the time- invariant characteristics of each borrower. Limitations In what follows, we note some features of our setting that may limit the gener- alizability of the empirical results. Concurrent Changes in Loan and Savings Products. As discussed in Section II, the shift from individual to group liability lending contracts was 450 THE WORLD BANK ECONOMIC REVIEW accompanied by other changes in the contract features. Specifically, in the group liability setting, the loan officers collected repayment from the group leader rather than from each individual borrower, monthly installments became fixed rather than varying, and the interest rate increased from 18 percent to 24 percent. Furthermore, simultaneous with the change to joint lia- bility loan products, the savings rules shifted because Saath began requiring all of its members to maintain compulsory savings accounts. In our view, an ideal experimental evaluation would include (1) requiring borrowers to enter joint liability lending groups rather than borrowing on their own and (2) loan officers collecting repayment from the group leader rather than from each individual borrower, leaving the installment sizes and the inter- est rate fixed. The group lending contracts offered by the majority of MFIs in India collect repayment either from one person (an assigned leader) or from every borrower in the group simultaneously. Hence, we believe that the change in the mode of payment is a feature of the group liability contract. Although the interest rate change and the change in monthly installments are not typical, our regression coefficients, which estimate the impact of the contract change, are likely to be lower bounds. In theory, the increase in the in- terest rate could have several effects: a price effect might reduce demand, whereas a higher interest rate could increase the repayment burden and induce default. Most evidence suggests that microfinance borrowers are not very price elastic, so we are not overly concerned about the demand effects. The increase in the interest rate should bias us against a finding that joint liability lending reduces default. Furthermore, our empirical analysis only considers individuals who borrowed under both the individual and group liability regimes, thus ac- counting for any self-screening among clients based on the increase in interest rates between the two loan contracts. The change in monthly repayment installments and the mode of payment also warrants further discussion. The repayment schedule for individual liabili- ty loans required fixed principal repayments along with interest. Hence, the nominal size of the monthly payments declined over the cycle of the loan. In contrast, the group liability repayment structure is based on a fixed monthly re- payment throughout the term of the loan. Because our analysis focuses on the shift from individual to joint liability loans for the same person, for the same loan amount, we pick up the effect of a lower payment under individual liabili- ty (because the borrower is at the end of her loan cycle) versus a relatively higher fixed payment under joint liability. This shift should bias us against finding a reduction in default. This bias effect is likely even greater in our case because the average loan size and the corresponding repayment installment size are higher under joint liability. The mode of payment also shifted under the individual and group liability settings. In the former, the field officer visited each individual liability borrower to collect repayment, whereas in the latter, the field officer only visited the group leader, who was in charge of collecting repayment from the other Carpena, Cole, Shapiro, and Zia 451 members. Nevertheless, this change in the mode of payment is a feature of group lending because in the setting that we study, group liability is a lending contract that involves both joint repayment to a group leader and joint liability. Thus, the “group” features, such as repayment to a group leader, may lower default, whereas the higher interest rates may increase default, so the effect that we capture may well be a lower bound. Saath’s savings products also changed during our study period, as discussed in Section II. However, we note first that in our main analysis of loan repay- ment and savings discipline, we focus only on the individuals who converted to group liability loans, exploiting the timing of their switch. This focus allows us to control for any changes that occurred at the microfinance institution level under the two loan contract regimes. Thus, in the context of the MFI-wide change in savings requirements, we are comparing a shift from individual to joint liability for the same person (when we include individual fixed effects) who faces mandatory savings under both liability structures. Because our em- pirical strategy rests on the continuous, rolling changeover from individual to joint liability after the announcement, our sample consists of borrowers who are opening and maintaining mandatory savings accounts prior to shifting to a joint liability loan. Although the introduction of a mandatory savings account may have influenced the composition of borrowers, the internal validity of our results remains unaffected because our analysis considers only those individuals who chose to renew their loans with Saath. Theoretically, the imposition of mandatory savings may have two opposing effects: (a) it may discourage borrowers from renewing their loans because the real cost of borrowing has increased through the imposition of a mandatory savings plan; or (b) it may encourage borrowers to renew their loans because individuals appreciate the saving discipline provided by compulsory accounts. This latter point is not trivial. Individuals may fail to save enough because they consistently put off saving for their future (Laibson, 1997), they may be tempted to spend on immediate consumption (Banerjee and Mullainathan, 2010), or they may face intra-household constraints (Ashraf et al., 2010). In a recent field experiment, Atkinson et al. (2010) find that prompting individuals to save at the time of loan repayment doubles the amount of savings. The overall effect of mandatory savings on borrower selection is therefore ambiguous. Unfortunately, we lack any household-level data that would allow us to empirically differentiate these effects. In addition, we only have basic socioeconomic data from Saath records for the clients who eventually joined the joint liability groups. Nevertheless, we run a simple regression of renewal on the percentage payments missed and find a strong statistically significant negative coefficient. Clearly, there is screening based on past loan performance. However, we also find that this screening occurs even for previous individual-to-individual renewals and therefore cannot be considered an effect of either joint liability or mandatory savings. 452 THE WORLD BANK ECONOMIC REVIEW EXTERNAL VALIDITY. Our study sample consists of individual borrowers who have repaid their individual loans and choose to borrow under joint liability. We therefore estimate the effect of joint liability on improving repayment rates among those who choose to borrow under joint liability. Although restricting our analysis to this sample may compromise external validity, we believe that this sample is highly relevant; measuring the effect on those who decline to borrow under joint liability would have little relevance for the outside world. Of course, the sample is also selected based on individuals who chose to borrow in an individual liability setting. However, given that most theory sug- gests that joint liability leads to stricter screening and stricter monitoring, this additional screen may not be that restrictive. The setting that we study may be anomalous in that the typical transition in the microfinance industry is presently the reverse, but we believe that careful study of the effects of shifts in liability in either direction is informative and valuable. Indeed, the recent collapse of Banco del Exito (BANEX), one of the largest microlenders in Nicaragua, highlights the importance of examining the relative merits of group liability and individual liability contracts. Furthermore, the main question that we ask—whether conditional on borrowing, liability rules impact repayment performance—has important policy and theoretical im- plications because we consider how joint liability lending may improve upon individual liability lending. It is difficult to imagine how any single study could capture both the compositional effects and the effect of contract structure on those who have borrowed in individual and joint liability settings. By focusing on clients who borrowed under both individual and joint liabili- ty, our study further highlights the importance of examining the impact of lending contracts on financial inclusion. In the setting that we study, almost 80 percent of the borrowers who completed their individual liability loan and could have borrowed under joint liability did not do so. Although this high percentage indicates that it is possible for the shift in joint liability to have neg- ative consequences on financial inclusion, we do not have data on why people chose to borrow or not to borrowwith Saath. Many new clients (who had not previously borrowed under individual liability) joined Saath after joint liability and may have chosen to stop borrowing for a number of reasons (e.g., no further project/investment needs, shifting business or employment status). Without further data, we cannot determine the impact of joint liability on fi- nancial inclusion. Finally, although we find strong evidence that joint liability improves upon individual liability lending in terms of repayment behavior, we cannot be certain that the treatment effect is similar for other MFIs. The MFI that we study, Saath, has operations that are fairly typical of small MFIs around the world. However,we evaluate a particular joint liability lending program in which borrower groups have a group leader who collects repayment for the group as opposed to public repayment (e.g., at the village center), a collection Carpena, Cole, Shapiro, and Zia 453 method that may bemore common among other MFIs. In this sense, the exter- nal validity of our findings may be limited. DATA LIMITATIONS. Because the data that are available were used primarily for accounting purposes, the dataset does not contain information on the terms of each loan, such as maturity dates, installment amounts, and outstanding loan amounts, all of which were recorded by loan officers in paper ledgers. Thus, our analysis is limited to observing whether a client made a loan repayment or a compulsory savings deposit for a particular month, and we are unable to con- sider outcomes on overdue loan amounts, prepayments, and other measures. Furthermore, aside from data on gender and the client’s neighborhood, the data do not contain information on other demographic or household character- istics of the clients. Because of data limitations, our ability to understand why borrowing amounts increase is limited. Under individual liability, borrowers were limited to loan amounts that were a fixed proportion of their savings and their guaran- tors’ savings. These restrictions were removed under joint liability and replaced with a strict appraisal process for group members. Ideally, if we had deposit data under individual liability, we could determine whether these borrowing constraints were binding under individual liability. Unfortunately, Saath did not keep good historical records of these data; hence, it is not possible to statis- tically distinguish demand and supply effects on loan size. Effect of Lending Structure on Loan Repayment We now turn to the critical question of loan repayment. We note that the joint liability structure will, in theory, induce not only better screening but also greater monitoring efforts. Our empirical design does not distinguish between the two potential causes of improved repayment but rather estimates the com- bined causal effect. Table 2 presents the OLS estimates of Equation 1, where the outcome of in- terest is a dummy variable for a missed payment. This dummy variable indi- cates whether the client failed to make a repayment for a particular month. Saath Microfinance clients are required to make monthly repayments until the principal balance is paid in full, beginning 30 days after disbursement. Hence, the dependent variable takes the value of 1 for a particular month if the total amount repaid by the borrower for that month is nil and 0 otherwise. We use this dummy variable as our first measure of monthly loan repayment discipline. In our sample, almost 20 percent of the individual liability but only 0.1 percent of the group liability monthly loan repayments were not made. Our main results are presented in Table 2. Column (1) presents the regression results with no fixed effects, controlling only for which branch the borrower uses. Taken at face value, group lending reduces the probability of missing a payment by 17.5 percentage points. In columns (2)-(4), we add individual fixed effects, calendar month fixed effects, and both sets of fixed effects, respectively. 454 T A B L E 2 . Dependent Variable: Missed Payment Dummy THE WORLD BANK ECONOMIC REVIEW (1) (2) (3) (4) (5) (6) Group Liability Loan Dummy 2 0.175*** 2 0.163*** 2 0.152*** 2 0.112*** 2 0.159*** 2 0.081** (0.014) (0.012) (0.042) (0.026) (0.015) (0.033) Behrampura Branch 0.067*** 0.072*** 0.067*** (0.016) (0.015) (0.016) Number of Previous Loans 2 0.008 0.045*** (0.007) (0.017) Loan Age in Months 2 0.028*** 2 0.014** (0.007) (0.007) Loan Age Squared 0.003*** 0.002*** (0.001) (0.001) Loan Age Cubed 2 0.000*** 2 0.000*** (0.000) (0.000) Constant 0.128*** 0.091*** 0.217** 0.181*** 0.167*** 0.272*** (0.013) (0.004) (0.087) (0.086) (0.020) (0.086) Control for Calendar Month No No Yes Yes No Yes Individual FEs No Yes No Yes No Yes R-squared 0.082 0.229 0.098 0.246 0.095 0.253 N 6055 6055 6055 6055 6055 6055 Mean of Dep Var 0.105 0.105 0.105 0.105 0.105 0.105 *p , 0.10, **p , 0.05, ***p , 0.01. Notes: This table reports the results from the OLS regressions using panel data from April 2005 to March 2009, where the dependent variable is a dummy for missing a payment. This dummy takes the value of 1 for a particular month if the total amount repaid by the borrower for that month is nil and 0 otherwise. The observations are at the loan-month level. The sample includes the loans of clients who received both an individual and a group lia- bility loan. The variable Group Liability Loan Dummy is a dummy variable equal to 1 if the loan is a group liability loan and 0 if it is an individual lia- bility loan. Behrampura Branch is a dummy for one of the two MFI branches in the sample. Number of Previous Loans is the number of loans that the client received before the current loan. Loan Age in Months is the difference between the month of the observation and the month when the loan was dis- bursed, plus 1. Standard errors, clustered at the individual level, are given in parentheses beneath each point estimate. Source: Authors’ analysis based on data sources discussed in the text. Carpena, Cole, Shapiro, and Zia 455 Finally, in columns (5) and (6), we add controls for the age of the loan: repay- ments may be higher early in the cycle, when borrowers are flush with cash, or later in the cycle, when borrowers seek to repay a loan to obtain a new one. The coefficient drops, although only coefficients (1) and (6) have 95 percent confidence intervals that (barely) do not overlap. Because only overdue loans last over 12 months, the loan age coefficients may “soak up” some of the treat- ment effect, particularly when individual and month fixed effects are present.7 Our preferred point estimate is column (4), which indicates that group lending reduces the probability of a missed payment by 11.2 percentage points. This effect is large and meaningful and may have significant implications for the profitability of a lender. INTERNAL VALIDITY. We conduct a number of robustness tests. First, we report a direct “falsification” test of our analysis by using data from our clients’ previ- ous individual-to-individual loan renewals. Specifically, we focus on the clients in our sample who had at least two individual liability loans. The sample is reduced because many clients did not have multiple loans in the past. Among these clients, we study whether the borrowing experience with the microlender is related to loan repayment; in other words, does having a second loan lead borrowers to repay more reliably? Table 5 presents these results and shows no significant effect on missed payments.8 A second concern regarding the internal validity of our analysis is the fact that joint liability contracts are a completely new contractual arrangement. In particular, because the arrangement is new, clients may be in a “honeymoon” period.9 During this period, clients may be on their best repayment behavior while they are learning the rules of the game. As they gain a betterunderstanding of the consequences of missing a payment, they may begin to behave more stra- tegically. To test for this “honeymoon” effect, we compare the default rates of new clients (i.e., first-time Saath borrowers) under the individual and joint liabil- ity regimes over our sample period. Specifically, we find that first-time Saath bor- rowers make late payments 49 percent of the time in the individual liability setting and 2 percent of the time under joint liability. Because we are comparing clients who are borrowing for the first time in either setting, this result suggests that the “honeymoon” effect does not drive clients’ repayment behavior. 7. A simple way to address the relationship between loan age and repayment status is to to restrict the sample to the first twelve months of repayment data: doing so with the same specifications as reported in Table 2 yields point estimates ranging from 2 .074 to 2 .153, statistically indistinguishable from each other, but all statistically different from 0 at the one percent level. 8. The specific date (November 2007) for the falsification test was not chosen arbitrarily (rather, it was precisely one year prior to the actual change in date), but we have conducted the analysis for all months at least one year before the policy change and find that our effect is dramatically larger than at any other date. Specifically, we re-ran our specification with each of the previous twelve months as our placebo date and found only two cases to be significant, but of much lower magnitude. 9. We thank an anonymous referee for raising this point. 456 THE WORLD BANK ECONOMIC REVIEW A third concern is that a client’s propensity to repay may be correlated with the time in the loan cycle. Specifically, clients may be more likely to make re- payments toward the end of their last individual liability cycle to ensure their eligibility for a group liability loan in the future. We note that this situation would bias estimates against finding that group liability improves borrower per- formance. Nevertheless, we investigate this possibility using an event-time re- gression with the dependent variable for missed payment as previously described, where the event is the conversion from an individual liability loan to a group liability loan. Figure 2 plots the coefficients for each event-time dummy. The first month of repayment in the group liability setting is time ¼ 0, the final repayment month for the individual liability loan is time ¼ 2 1, the second-to-last individ- ual liability loan repayment month is time ¼ 2 2, and so on. Thus, the figure describes loan repayment behavior under the individual liability contract before switching to group liability. Saath requires its borrowers to pay their current loan in full before they are given their next loan. Therefore, by defini- tion, all clients in our sample made a repayment at time ¼ 2 1. Examining the periods in which time  7 2 2 reveals no pattern to support the idea that clients strategically repaid their individual liability loans so that they could borrow under the group liability setting. Alternatively, clients may be more likely to make repayments early in the loan cycle because they may be flush with cash from a recent loan disbursal. We examine this possibility, again using an event-time regression, as shown in Figure 3. We estimate how repayment rates change around loan renewal times when a client pays off an individual liability loan and renews another individu- al liability loan (blue line) as well as cases in which a client pays off a group li- ability loan and renews a second group liability loan (red line). Note that the first month of repayment in the second loan cycle is time ¼ 0, and the final re- payment in the first loan cycle is time ¼ 2 1. Similar to Figure 2, at time ¼ 2 1, all of the clients made a repayment by definition, so the missed payment dummy must mechanically equal zero. Figure 4 shows that the prior missed payments are uncorrelated with the number of months since loan origination. Our study sample consists of individual liability clients who chose to renew their borrowing under the group liability setting. These clients may be better at repayment than borrowers who did not want to enter into a group liability loan contract. However, our analysis focuses exclusively on those who renew and includes individual fixed effects. Hence, an interpretation of our results is that even “good” clients exhibited higher repayment discipline under the group liability setting in comparison with the individual liability setting. However, we acknowledge that by focusing only on those clients who borrowed under both types of contracts, we limit the external validity of our results. The outcome that we have considered thus far, whether a client missed a loan installment for a particular month, is a rough measure because repay- ments may be partial. That is, a client may have repaid an amount greater than Carpena, Cole, Shapiro, and Zia 457 F I G U R E 2. Event Time Regression: Missed Payment on Event Time Dummies of Switching from Individual to Group Liability Loan Notes: This figure plots coefficients for the event-time dummies where the event is the conversion from an individual liability to a group liability loan. The dependent variable is a dummy for missing a monthly repayment, which takes the value 1 for a particular month if the total amount repaid by the borrower for that month is nil and 0 otherwise. The first month of repayment in the group liability setting is time ¼ 0; the final repayment month in the individual liability setting is time ¼ 2 1. The dashed lines indicate the 95 percent confidence interval. Source: Authors’ analysis based on the data sources discussed in the text. zero but less than the required installment amount. Thus, another measure of repayment discipline is the standard deviation of the principal amount repaid for individual liability loans and the total amount repaid for group liability loans. As described in Section 2, only the principal installment amount is fixed in the individual liability setting, whereas in group liability, the required total installment amount ( principal plus interest) is equal every month. If the 458 THE WORLD BANK ECONOMIC REVIEW F I G U R E 3. Event Time Regression: Missed Payment on the Event Time Dummies for Switching from the First to the Second Loan Cycle Notes: This figure plots the coefficients for the event-time dummies where the event is the shift from the client’s first loan cycle to the second loan cycle for each of the individual and group liability loans. The dependent variable is a dummy for missing a monthly repayment, which takes the value 1 for a particular month if the total amount repaid by the borrower for that month is nil and 0 otherwise. The first month of repayment in the second loan cycle is time ¼ 0, and the final repayment month in the first loan cycle is time ¼ 2 1. The dashed lines indicate the 95 percent confidence interval. Source: Authors’ analysis based on the data sources discussed in the text. required amount is repaid each month, then the standard deviation would be zero. However, if there are many months in which people pay less or more than the required amount, then the standard deviation would be higher. Table 6 provides OLS estimates in which the dependent variable is the standard deviation of repayment. Again, our estimates show that there is greater loan Carpena, Cole, Shapiro, and Zia 459 F I G U R E 4. Calendar Month of Loan Origination and Missed Payments Notes: This figure plots the percentage of monthly repayments that were missed using the first three repayments from the loan disbursement of the client’s most recent individual liability loan. The calendar month of loan origination refers to the calendar month when the loan was disbursed. The size of the bubbles represents frequencies. The red line represents the best-fit line. The sample includes clients who received both an individual and a group liability loan. Source: Authors’ analysis based on the data sources discussed in the text. repayment discipline in the group liability setting relative to individual liability, although this effect is not statistically significant. Finally, we note that the average loan size increased from 10,000 INR under individual liability to 18,000 INR under joint liability (see Table 1). This in- crease is large and warrants further discussion. In some ways, the increase can be thought of as an effect of the group lending model because Saath was willing to extend larger loans to borrowers on the strength of social collateral. Indeed, Saath management told us that they were willing to give larger loans precisely because of the joint liability framework. However, one may reasonably wonder whether the increase in loan size itself affects repayment rates. For example, if borrowers invest in convex pro- duction technologies, higher credit limits could increase repayment. We test for this possibility in two ways. First, we split the sample into four quartiles based on the percentage increase in the credit limit from which a borrower benefited when she or he converted to joint liability lending. We do not observe any sys- tematic variation in the treatment effect estimate along this dimension (results not reported). Second, because our dataset includes the reported purpose of each group liability loan, we can conduct separate analyses for loans taken for the purpose of consumption, productive activities, and asset creation. Again, we find no evidence that the treatment effect varies across these three categories (results not reported). 460 THE WORLD BANK ECONOMIC REVIEW DISCUSSION. Given these results, a natural question that arises is why group lia- bility outperforms individual liability for clients who are already borrowing. Although the guarantors requirement in individual liability contracts provided incentives for guarantors to monitor loans and enforce repayment, in practice, these incentives were quite weak; the microlender rarely seized the savings of the guarantors of defaulting clients and did not strictly enforce that the guaran- tors maintain their savings account balance. The microlender collected repay- ment from the guarantors only if all other options (e.g., seizing the defaulting borrower’s savings, revisiting the defaulting borrower, threatening to charge penalties, rescheduling the loan, and having the branch manager intervene) had been exhausted. In contrast, the group liability structure strengthens coopera- tion and trust among the group members, as indicated by the fact that almost all of the joint liability borrower groups designate a group leader, even though it is not required. It is possible that having a group leader increases incentives for monitoring and enforcing repayment. For example, having a group leader may create a person of authority who can enforce repayment or impose sanc- tions in the event of default. We also note that the borrowing requirements for individual liability loans suggest that the effects that we find would likely be smaller in magnitude if these requirements were not in place. Because individual liability loan borrow- ers must have two guarantors and because Saath may use the guarantors’ savings in the event of default, it is possible that these requirements encourage the screening of potential individual liability loan borrowers. We are not able to control for such effects. Savings Discipline We now turn our attention to the compulsory savings deposits required by Saath. As discussed in Section I, we might expect savings to be higher in the joint liability setting because participating in a borrower group may allow indi- viduals to avoid financial demands from their families or to overcome self- control problems. Furthermore, compulsory savings are required to continue as a member in good standing with Saath; those who do not meet the compulsory savings requirements are not allowed to borrow until these requirements have been met. Thus, the same form of peer pressure that applies to loan repayment may apply to compulsory savings. Although Saath initiated both a shift to group liability lending and compul- sory deposits in November 2007, we can separately identify the effect of group liability on compulsory savings by exploiting the time-series variation in loan renewals. Specifically, although the compulsory savings were mandated across the board for all borrowers after November 2007, the shift from individual to group liability was staggered depending on when each individual loan term expired. As explained previously, these renewals were distributed relatively uni- formly throughout the year, resulting in variations in loan contracts at a time when compulsory savings were uniform. Hence, we can study adherence to Carpena, Cole, Shapiro, and Zia 461 compulsory savings for the same person who borrowed under an individual lia- bility contract after November 2007 and who eventually converted to a group liability contract.10 Table 3 presents the OLS estimates in which our dependent variable is a dummy for missing a compulsory savings deposit. The dependent variable takes the value of 1 if the client deposited less then INR 100 and 0 otherwise. The point estimate in column (4), which includes month and individual fixed effects, indicates that the same borrower is 20.5 percentage points less likely to miss a compulsory deposit in a group lending arrangement than when borrow- ing individually. This finding suggests that one possible mechanism through which group lia- bility reduces loan delinquency may be increased savings; a greater savings balance may provide a buffer for borrowers hit with liquidity shocks. Heterogeneous Effects We test for heterogeneous effects along two dimensions. As before, our depen- dent variable is a dummy for whether a client missed a loan repayment for a particular month. Columns (1)-(3) indicate a significantly larger impact of group liability in reducing missed payments among men, although the effect for women remains negative and significant. It is important to note, however, that the control group means for females are also significantly lower, with missed payment rates at 16 percent for females and 23 percent for males.11 The results suggest that group liability effectively neutralizes this gender differ- ential in missed payments. In columns (4)-(6), we examine whether group lending improves repayment behavior more for clients who initially exhibited poor repayment discipline under individual liability. We define ‘borrower quality’ as the percentage of missed payments in the client’s first individual liability loan in the data, and we divide the sample in two along this measure. Note that because our definition of borrower quality makes use of a client’s repayment behavior in her first indi- vidual loan, the regression columns (4)-(6) are restricted to the subsample of clients who had at least two individual loans and include repayment data only from the client’s second individual loan onwards. In terms of past missed payments, we find that group liability has a larger impact on borrowers who, at the outset, were of poor quality. Clients who missed 10 percent of their first individual loan monthly payments were 2.4 percent less likely to miss repayments under the group liability regime. Hence, similar to the gender results, the introduction of group liability is effective in reducing missed payments among those with inconsistent payment records. 10. because we only have savings data from January 2008 onwards, we cannot study the effect of compulsory savings under the individual liability setting, as we have no pre-period data (i.e. savings data pre-November 2007). 11. A difference in means test is significant at the 1 percent level. 462 T A B L E 3 . Dependent Variable: Missed Compulsory Deposit THE WORLD BANK ECONOMIC REVIEW (1) (2) (3) (4) (5) (6) Group Liability Loan Dummy 2 0.234*** 2 0.338*** 2 0.074* 2 0.205** 2 0.230*** 2 0.198*** (0.035) (0.032) (0.041) (0.045) (0.038) (0.069) Behrampura Branch 0.003 2 0.008 2 0.000 (0.036) (0.034) (0.035) Number of Previous Loans 2 0.001 0.124 (0.017) (0.098) Loan Age in Months 2 0.040** 0.050*** (0.019) (0.019) Loan Age Squared 0.004 2 0.006** (0.003) (0.003) Loan Age Cubed 2 0.000 0.000** (0.000) (0.000) Constant 0.389*** 0.698*** 0.607*** 0.807*** 0.461*** 0.623*** (0.039) (0.027) (0.045) (0.040) (0.049) (0.123) Control for Calendar Month No No Yes Yes No Yes Individual FEs No Yes No Yes No Yes R-squared 0.054 0.489 0.103 0.511 0.059 0.514 N 2929 2929 2929 2929 2929 2929 Mean of Dep Var 0.205 0.205 0.205 0.205 0.205 0.205 *p , 0.10, **p , 0.05, ***p , 0.01. Notes: This table reports the results from the OLS regressions with panel data from January 2008 to March 2009, where the dependent variable is a dummy for missing a compulsory deposit. This dummy takes the value of 1 for a particular month if the client deposited less than the required amount of Rs. 100 and 0 otherwise. The observations are at the individual-month level. The sample includes clients who received both an individual and a group lia- bility loan. The variable Group Liability Loan Dummy is a dummy variable equal to 1 if the client had a group liability loan and 0 if it is an individual li- ability loan. Behrampura Branch is a dummy for one of the two MFI branches in the sample. Number of Previous Loans is the number of loans that the client received before the current loan. Loan Age in Months is the difference between the month of the observation and the month when the loan was dis- bursed, plus 1. Standard errors, clustered at the individual level, are given in parentheses beneath each point estimate. Source: Authors’ analysis based on data sources discussed in the text. T A B L E 4 . Heterogeneous Effects by Gender and Borrower Quality (1) (2) (3) (4) (5) (6) Group Liability Loan Dummy 2 0.224*** 2 0.212*** 2 0.132*** 2 0.137*** 2 0.122*** 2 0.075 (0.034) (0.032) (0.042) (0.028) (0.025) (0.048) Female 2 0.041 (0.039) Group Liability Loan* 0.063* 0.065* 0.070** Female (0.037) (0.035) (0.032) Borrower Quality 0.223** (0.111) Group Liability Loan* 2 0.234* 2 0.240* 2 0.248** Borrower Quality (0.119) (0.123) (0.121) Behrampura Branch 0.061*** 0.079*** (0.017) (0.024) Number of Previous Loans 0.045*** 0.025 (0.017) (0.023) Carpena, Cole, Shapiro, and Zia Loan Age in Months 2 0.014* 0.012 (0.007) (0.008) Loan Age Squared 0.002*** 2 0.001 (0.001) (0.001) Loan Age Cubed 2 0.000*** 0.000 (0.000) (0.000) Constant 0.165*** 0.108*** 0.296*** 0.088*** 0.075*** 0.147 (0.038) (0.011) (0.087) (0.022) (0.010) (0.144) Individual FEs No Yes Yes No Yes Yes Month FEs No No Yes No No Yes R-squared 0.084 0.231 0.255 0.095 0.239 0.268 N 6055 6055 6055 2579 2579 2579 463 (Continued ) 464 THE WORLD BANK ECONOMIC REVIEW TABLE 4. Continued (1) (2) (3) (4) (5) (6) Mean of Dep Var in Control (Males) 0.226 0.226 0.226 Mean of Dep Var in Control (Females) 0.157 0.157 0.157 *p , 0.10, ** p , 0.05, ***p , 0.01. Notes: This table reports the results from the OLS regressions where the dependent variable is a dummy for missing a payment. This dummy takes the value of 1 for a particular month if the total amount repaid by the borrower for that month is nil and 0 otherwise. The regressions in columns 1 to 3 provide the heterogeneous effects by gender and include the full sample of clients. The regressions in columns 4 to 6 provide the heterogeneous effects by borrower quality, defined by the percentage of missed payments in the client’s first individual liability loan in the data. The regressions in columns 4 to 6 include only the subsample of clients who had at least two individual liability loans and only loans from the 2nd loan onwards. All of the observations are at the loan-month level. The variable Group Liability Loan Dummy is a dummy variable equal to 1 if the loan is a group liability loan and 0 if it is an individual liability loan. Borrower Quality is the percentage of missed payments in the client’s first individual liability loan in the data. Behrampura Branch is a dummy for one of the two MFI branches in the sample. Number of Previous Loans is the number of loans that the client received before the current loan. Loan Age in Months is the difference between the month of the observation and the month when the loan was disbursed, plus 1. Standard errors, clustered at the individual level, are given in parentheses beneath each point estimate. Source: Authors’ analysis based on data sources discussed in the text. TA B L E 5 . Falsification Test (1) (2) (3) (4) (5) (6) False Treatment 2 0.004 2 0.011 0.049 0.002 0.021 0.058 (0.023) (0.026) (0.041) (0.025) (0.025) (0.050) Behrampura Branch 0.076*** 0.089*** 0.066*** (0.027) (0.027) (0.029) Number of Previous Loans 2 0.028** 0.046 (0.014) (0.035) Loan Age in Months 2 0.025 2 0.014 (0.019) (0.022) Loan Age Squared 0.003 0.004 (0.003) (0.003) Loan Age Cubed 2 0.000 2 0.000 (0.000) (0.000) Constant 0.095*** 0.058*** 0.222 0.139*** 0.158*** 0.319** (0.025) (0.013) (0.142) (0.020) (0.043) (0.129) Control for Calendar Month No No Yes No No Yes Individual FEs No Yes No No No Yes Carpena, Cole, Shapiro, and Zia R-squared 0.011 0.140 0.042 0.000 0.016 0.175 N 1584 1584 1584 1584 1584 1584 Mean of Dep Var 0.140 0.140 0.140 0.140 0.140 0.140 *p , 0.10, **p , 0.05, ***p , 0.01. Notes: This table reports the results from a falsification test, where the dependent variable is a dummy for missed payment. This dummy variable takes on the value of 1 for a particular month if the total amount repaid by the borrower for that month is nil and 0 otherwise. The regressions corre- spond with those in Table 2. The sample contains the observations of the individual liability loans among clients who received both an individual and a group liability loan and who obtained at least 2 individual liability loans, the most recent of which was disbursed after November 2006. Observations are at the loan-month level. False Treatment is a dummy variable equal to 1 if the loan was disbursed after November 2006 and 0 otherwise. Behrampura Branch is a dummy for one of the MFI branches in the sample. Number of Previous Loans is the number of loans that the client received before the current loan. Loan Age in Months is the difference between the month of the observation and the month when the loan was disbursed, plus 1. Standard errors, clustered at the individual level, are given in parentheses beneath each point estimate. Source: Authors’ analysis based on data sources discussed in the text. 465 466 THE WORLD BANK ECONOMIC REVIEW T A B L E 6 . Dependent Variable: Standard Deviation of Repayment (1) (2) (3) Group Liability Loan Dummy 2 288.666 2 306.367* 2 220.794 (185.204) (185.391) (251.901) Behrampura Branch 839.101*** (149.442) Constant 1352.427*** 798.894*** 281.277*** (100.308) (120.412) (83.967) Individual FEs No No Yes R-squared 0.005 0.041 0.472 N 689 689 689 Mean of Dep Var 1243.496 1243.496 1243.496 *p , 0.10, **p , 0.05, ***p , 0.01. Notes: This table reports results from the OLS regressions using cross-sectional data, where the dependent variable is the standard deviation of monthly repayment. If the required amount is repaid every month, then the standard deviation would be zero. If there are many months where people pay less or more than the required amount, then the standard deviation would be higher. The observations are at the loan level. The sample includes the loans of clients who received both an individual and a group liability loan. The variable Group Liability Loan Dummy is a dummy variable equal to 1 if the loan is a group liability loan and 0 if it is an individual liability loan. Behrampura Branch is a dummy for one of the two MFI branches in the sample. Standard errors, clustered at the individual level, are given in parentheses beneath each point estimate. Source: Authors’ analysis based on data sources discussed in the text. V. D I S C U S S I O N AND CONCLUSION Microfinance has reached over 150 million borrowers worldwide and is growing at a cumulative 40 percent average growth rate. Recent initial public offerings (IPOs), which valued the Mexican microfinance institution Compartamos at $2 billion and SKS in India at $1.5 billion, have attracted the attention of the global financial markets. However, there have also been spec- tacular failures, such as the collapse of Banco del Exito (BANEX), which was recently the largest micro, small, and medium enterprise lender in Nicaragua, with a $125 million dollar loan portfolio. Suffering from a 45 percent delin- quency rate, BANEX was ordered into liquidation.12 As many microlenders around the world weaken their group liability ap- proach and shift toward individual lending, understanding the role of group li- ability in enhancing performance has become critical in microfinance programs. However, the empirical literature provides little guidance for policy makers and microfinance practitioners because few empirical studies have com- pared group liability contracts with other lending strategies. In this paper, we exploit an exogenous change in the liability structure in an Indian microfinance program, in which the program shifted from an individual liability structure to a group liability structure. We find evidence that for the 12. See: http://financialaccess.org/node/3547 Carpena, Cole, Shapiro, and Zia 467 same borrower, the shift to group liability reduces default rates and improves savings discipline. Under the group liability setting, the required monthly loan installments are 11 percent less likely to be missed, and compulsory savings de- posits are approximately 20 percent less likely to be missed relative to individu- al liability. Thus, our findings indicate that group lending outperforms individual lending in loan repayment and savings discipline. We see our study as an important piece of evidence rather than a definitive answer to the question of the optimal lending structure for microfinance. The microlender that we study, Saath, has operations that are fairly typical of MFIs that lend in urban areas. Moreover, the management, infrastructure, and stated goals of Saath are not markedly different from other lenders throughout India or in other low-income settings. Saath’s most remarkable characteristic is prob- ably its small size; the microfinance industry includes an important right tail of very large lenders. However, small institutions such as Saath (an NGO with $410,000 dollars in its total loan portfolio as of 2009) make up a non-trivial portion of the industry. Second, as with any natural experiment, we caution that there are limita- tions to our study. Our sample consists of only those who elected to continue from the individual to the group lending model and thus may not be represen- tative of the entire population that would be effected by changes in lending models. We are unable to clearly identify the mechanisms through which group lending improves repayment, and our data are not sufficient to allow us to pre- cisely calculate the effect of the lending structure change on lender profitability. An ideal experiment to answer these questions might have randomly assigned individuals to a range of different lending models, such as group lending with self-selected group members, group lending with randomly assigned group members, and group lending without group liability. Nevertheless, it may be useful to discuss our view of the mechanisms at work based on our reading of the evidence and on numerous conversations with Saath clients, staff, and management. We believe that peer pressure is im- portant. The Saath operations manual states, “The concept of peer pressure must be executed properly in favor of the organization and concept of micro finance,” arguing that the group leader should take responsibility for ensuring that the members repay and stressing the importance of joint liability. In the case of repeated missed payments, the manual instructs staff to ensure that “the members take the responsibility of closing the loan amount of” a delin- quent borrower. We also interviewed 10 Saath field officers regarding their views of changes to the loan collection process with group lending. All ten field officers mentioned that collection under joint liability was easier because clients were more disciplined about paying on time, and several others men- tioned the importance of “collective responsibility” within the group. These qualitative reports are consistent with a recent paper on microfinance in Andhra Pradesh, which finds that peer pressure is an important determinant of loan repayment (see Breza (2012)). 468 THE WORLD BANK ECONOMIC REVIEW Taken as a whole, we believe that our results provide a cautionary tale for policy-makers and microfinance institutions that are eager to convert from group to individual lending models. Although most microfinance organizations around the world have reported repayment rates that are impressively high, the industry has also witnessed both idiosyncratic failure and widespread collapse, such as the recent crisis in Andhra Pradesh. Our results highlight the impor- tance of the group lending structure in facilitating the sustainable provision of credit to the poor. 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