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The impact of agricultural extension services : a review of the literature (English)

This paper provides a review of the literature on the effectiveness of agricultural extension services worldwide. It shows that evaluators of the internal effectiveness of extension services are generally critical; they claim that extension services have poor performance, reach only a small proportion of farmers, have wrong objectives, and are of little help to the agricultural sector as a whole. The author argues that this diagnosis may be excessive, that evaluators often have irrelevant evaluation criteria, and that historically the situation has substantially improved. Evaluators of external efficiency, mainly economists, show much more positive results. Those who use aggregate data find high social rates of return to investment in extension services and high correlations between extension services and agricultural productivity, but the methods used tend to overestimate the specific impact of extension services. Those who use farm-level data obtain mixed results, about half with significantly positive regression coefficients but of low value, and the other half with nonsignificant regression coefficients.

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The impact of agricultural extension services : a review of the literature (English). Development Economics Population & Human Resources,no. DPH 8120 Washington, D.C. : World Bank Group.