Beyond average: are the yield and income impacts of adopting drought-tolerant maize varieties heterogeneous?

Abstract

Assessing the benefits of adopting climate-resilient farming technologies without considering the heterogeneity among farmers, may not provide a sufficient evidence base for policy. Yet, most empirical studies do not go beyond documenting the average effects of climate-resilient technologies. Using farm household survey data from Nigeria, this paper examines whether and to what extent the yield and income impacts of adopting drought-tolerant maize varieties are heterogeneous. We used the stratification-multilevel, matching-smoothing and smoothing-differencing econometric methods to analyse the heterogeneous effects of the varieties on maize yield, crop income and household income. Our results show that the adoption of drought-tolerant maize varieties significantly increased maize yield, crop and household income. In addition, we find that the yield and income impacts of the adoption of drought-tolerant maize varieties are heterogeneous and depend on the farm households’ propensity to adopt the drought tolerant maize varieties. Specifically, we find that the estimated yield effects of the drought-tolerant maize varieties are larger for farmers with the highest propensity to adopt the varieties, which suggests a positive selection. Our results emphasize the need for proper targeting of interventions to incentivize the uptake of climate-resilient farming technologies in order to improve the outcomes of households in drought-prone areas.