Economywide Impact of Maize Export Bans on Agricultural Growth and Household Welfare in Tanzania: A Dynamic Computable General Equilibrium Model Analysis

In recent years, the government of Tanzania, like other governments in Africa south of the Sahara, has periodically banned the export of staple crops (maize) in an attempt to ensure the domestic food supply and protect its citizens from international food price hikes. While this policy seems to be a common response to domestic production shortfalls or to high prices in international or neighboring countries’ markets, export bans not only have the potential to reduce producer prices locally but also, because the bans are often ad hoc, can cause significant market uncertainty for farmers and the private sector, ultimately making them less responsive in both supply and trade opportunities in the future. While complaints by farmers and traders regarding the export bans frequently appear in the newspapers in Tanzania, few rigorous analyses have been done to quantitatively measure the impacts of the policy. Given this knowledge gap and policy demand, we study the impact of export bans in Tanzania using a computable general equilibrium model.

We find that although maize is an important food crop in Tanzania, its contribution to food price inflation is rather limited, and that banning cross-border maize exports lowers the national food price index by only 0.6–2.4 percent compared with the free-export scenario. The benefits of lower prices are captured primarily by urban households, but maize producer prices decrease by 7–26 percent, depending on the region. We also find that the export ban decreases the wage rate for low-skilled labor and the returns to land, while returns to nonagricultural capital and wage rate for the skilled labor increase, further hurting poor rural households and thus increasing poverty for the country as a whole.