The Role of Soil Conservation on Mean Crop Yield and Variance of Yield - Evidence from the Ethiopian Highlands

Land degradation has been one of the major areas of concern in Ethiopia. Governments and development agencies have invested substantial resources to promote land management technologies and reduce land degradation. However, there is little understanding of the impacts that land management technologies have on yield and yield variability. This paper investigates the impact of stone bunds on mean yield and variance of yield, using multiple plot observations per household in low- and highrainfall areas of the Ethiopian highlands. Our analysis incorporated the propensity score matching method, stochastic dominance analysis, and exogenous and endogenous switching regression methods. We found statistically significant and positive impact of stone bunds on yield in low-rainfall areas. This did not hold in high-rainfall areas. We did not find a statistically significant stone-bund impact on production risk in either high- or low-rainfall areas. The results were robust to both parametric and nonparametric analysis. The overall conclusion from the analysis is that the performance of stone bunds varies by agro-ecology type. This implies the need for designing and implementing appropriate technologies that enhance productivity and are better adapted to local conditions.