This paper explores the relationship between agricultural productivity and rural–urban migration by developing an econometric model and applying it to the case of Senegal. Country level data is used covering the years 1961–1996. Policy implications of reducing rural–urban migration using agricultural output elasticities are developed. The findings support the hypothesis that rural–urban migration is a positive function of the ratio of urban per capita income to rural per capita income. Moreover, the results support a policy aimed at reducing rural–urban migration flows through increases in per capita earnings derived from increased agricultural investment.