Estimating the Effectiveness of Public Versus Private Distribution Systems: Insights from a Fertilizer Policy Reform in Malawi
利用马拉维2015/16年度的政策改革，通过双重差分法比较公共和私人渠道向小农户分配补贴肥料的效率，发现私人渠道使农户更早获得肥料，但对产量等影响不显著。
Throughout much of the world, critical goods and services are provided by parallel public and private distribution systems. However, it is often difficult to causally differentiate the performance of these two channels. In this article, we utilize a policy change in Malawi to estimate the relative efficiency of public and private channels in distributing inputs to smallholder farmers. In the 2015/16 agricultural season, the government allowed a group of private-sector fertilizer dealers to distribute subsidized fertilizer in nine of the country’s 28 districts. We use a panel dataset and a difference-in-differences (DID) strategy to estimate the impact of the pilot reform on a set of variables encompassing the entire process of subsidized fertilizer acquisition and appropriate utilization. We find that households in districts where the private sector distributed subsidized fertilizer were 11 percentage points more likely to acquire it earlier in the planting season (p < 0.01). We also find that households in pilot districts were six percentage points more likely to apply inorganic fertilizer (p < 0.10), but this effect was no longer statistically significant after using household fixed-effects and correcting for multiple hypothesis testing. Additionally, the reform did not affect other outcomes such as timely fertilizer application or maize yields.