Is fertiliser use inconsistent with expected profit maximization in sub‐Saharan Africa? “Evidence from Nigeria”
重新审视了撒哈拉以南非洲化肥使用率过低的观点，发现农民行为与预期利润最大化并不矛盾，因为水稻对氮肥的产量反应低、运输成本高且农村售价低。
Abstract This article revisits a conventional wisdom that inorganic fertiliser use across sub‐Saharan Africa is too low. This expectation that more farmers should be using inorganic fertiliser, and at higher rates, implies it is profitable to use rates higher than observed if farmers are rational expected profit maximisers. We obtain consistent estimates of the effects of applied nitrogen on rice production. We find the yield response to applied nitrogen to be low in the main rice growing farming system. Farmer behaviour is not inconsistent with expected profitability which is limited by a low yield response to applied fertiliser, high transportation costs, and low selling prices for rice in rural areas. In particular, we do not find any farmers for whom applied nitrogen is profitable that are not using fertiliser in the study sample for each of our survey years (2010 and 2012).