Economics of Agricultural Extension Services:a Review of Cost-effectiveness, Adoption Impact, and Returns to Investment
DOI:
https://doi.org/10.48165/asl.2025.1.02.01Keywords:
agricultural extension, cost-effectiveness, technology adoption, returns to investment, benefit-cost ratio, ICT, Farmer Field Schools, rural developmentAbstract
Background: Agricultural extension services represent a critical institutional mechanism for bridging the gap between research-generated knowledge and on-farm application. Despite decades of investment, rigorous economic evaluation of extension's cost-effectiveness and developmental impact remains fragmented. Objective: This paper synthesizes the empirical literature on the economics of agricultural extension, examining cost-effectiveness, technology adoption impacts, and returns to investment (ROI) across delivery models, regions, and commodity systems. Methods: We reviewed 84 peer-reviewed studies published between 1990 and 2023, identified through systematic searches of Web of Science, Scopus, and Google Scholar. Studies were included if they provided quantitative estimates of extension costs, adoption rates, productivity impacts, or BCR/ROI metrics. Results: Median benefit-cost ratios (BCRs) range from 2.1 for traditional public extension to 7.2 for ICT-enabled platforms. Farmer Field Schools (FFS) consistently outperform Training and Visit (T&V) approaches in technology adoption (mean adoption gain: +23 pp vs. +11 pp). Returns to investment average 48% per annum across Sub-Saharan Africa and 55% in South Asia, but exhibit high heterogeneity by commodity and agroecological zone. Conclusions: Extension investment remains highly profitable when targeted to binding knowledge constraints. Pluralistic, technology-augmented models offer superior cost-effectiveness, but demand complementary investments in connectivity, input markets, and farmer literacy.
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