Year Published

Research Topics



EPAR Technical Report #354
Publication Date: 11/29/2018
Type: Research Brief

Precise agricultural statistics are necessary to track productivity and design sound agricultural policies. Yet, in settings where intercropping is prevalent, even crop yield can be challenging to measure. In a systematic survey of the literature on crop yield in low-income settings, we find that scholars specify how they estimate the yield denominator in under 10% of cases. Using household survey data from Tanzania, we consider four alternative methods of allocating land area on plots that contain multiple crops, and explore the implications of this measurement decision for analyses of maize and rice yield. We find that 64% of cultivated plots contain more than one crop, and average yield estimates vary with different methods of calculating area planted. This pattern is more pronounced for maize, which is more likely than rice to share a plot with other crops. The choice among area methods influences which of these two staple crops is found to be more calorie-productive per ha, as well as the extent to which fertilizer is expected to be profitable for maize production. Given that construction decisions can influence the results of analysis, we conclude that the literature would benefit from greater clarity regarding how yield is measured across studies.

EPAR Research Brief #42
Publication Date: 07/31/2009
Type: Research Brief

Nigeria’s experience with fertilizer subsidy programs has been different than that of other countries in Sub-Saharan Africa. Nigeria is one of the only African countries capable of producing fertilizer domestically. But Nigeria is also large and densely populated. This makes national agricultural policy difficult due to logistical problems with implementation and the unique fertilizer needs of the various agro-ecological zones. This research brief discusses the effects of Nigeria’s input subsidy programs on maize production and fertilizer consumption. It focuses on the years 2000 to 2007, but also includes a discussion of Nigeria’s subsidy history from the early 1970s to 2009. Researchers have had difficulty studying Nigeria’s subsidy schemes due to a lack of data. In spite of decades of authoritarian, centralized leadership, Nigeria’s states have significant power to implement their own subsidies. This complicates any evaluation of a program’s effectiveness, in part due to the variety of subsidies at any given time, as well as inconsistent accounting practices.