Empirical effects of short-term export bans: The case of African maize

- Export bans in East and Southern Africa have no effect on cross-border price gaps.
- Export bans appear to increase prices and volatility in the implementing country.
- Imperfect enforcement diverts trade while uncertainty destabilizes markets.
- Policy-makers should reconsider the use of bans for price stabilization purposes.

Temporary export restrictions have been widely used in recent years in an attempt to stabilize domestic prices of staple grains. I use monthly, market-level price data to investigate the empirical effects of 13 short-term export bans on maize implemented by 5 countries in East and Southern Africa. I find no statistically significant effect of export bans on the price gaps between pairs of affected cross-border markets. My results for price gaps match those from a model simulation in which export bans are not implemented. However, prices and price volatility in the implementing country are significantly higher during export ban periods in the data than in the model simulation with no bans. Export bans in the region are imperfectly enforced, divert trade into the informal sector, and appear to destabilize domestic markets rather than stabilizing them.