Deterring Industrial Vessels from African Coastal Fisheries

Most African coastal nations prohibit industrial vessels from fishing near their shores; these Inshore Exclusion Zones (IEZs) reserve the most productive locations for small-scale, artisanal fishers. However, previous descriptive research suggests that non-compliance by industrial vessels prevents IEZs from benefiting African economies, food security, and fish stocks. Radar data released in 2024 detect industrial vessels without selection, enabling the first causal evaluation of African IEZs. First, regression discontinuity estimates reveal that 6 of 20 African countries successfully deter industrial fishing vessels (Nigeria, Sierra Leone, Liberia, Mauritania, Ghana, and Guinea). Second, bunching estimators obtain counterfactual vessel distributions that are uncontaminated by spillovers outside IEZ boundaries. Third, extensive‑margin effects are captured by calibrating a discrete choice vessel location model to the bunching estimates. Back‑of‑the‑envelope bioeconomic calculations indicate that IEZs increase annual artisanal fisher catch by 324 thousand tons—enough to meet key micronutrient requirements for 6.3 million people—without reducing industrial catch.