Impact of Improved Maize Varieties on Production Efficiency in Nigeria: Separating Technology from Managerial Gaps

Abstract

Researchers and policymakers are concerned about the substantial and increasing yield gap between sub-Saharan Africa and the rest of the world. High-yielding improved varieties are widely perceived as a means to close this gap. This study combines impact evaluation and production analysis techniques, which mitigate estimation biases stemming from observed and unobserved heterogeneity, to estimate the effects of improved varieties on maize productivity using a unique, recent, and nationally representative household survey. A linear endogenous treatment–effect model based on a matched sample obtained from propensity score matching indicated that the improved maize varieties increased yield by 38.7%. Simultaneously, selectivity-corrected and stochastic metafrontier approaches show that the yield advantage of improved varieties is mainly due to technological change; however, the technical efficiency of improved varieties is similar to those of traditional varieties.