Recent research suggests that adopting a common currency increases bilateral trade. In this paper, I explore experiences of currency union entry in the post-war period and find no effect on trade. Previous results derived from a large panel data set (covering more than 200 countries from 1948 through 1997) appear to depend crucially on the assumption of symmetry between currency union exits and entries: While countries leaving a currency union experience significant declines in trade, currency union entry appears to have no measurable effect on trade. Also, in a detailed analysis of the enlargement of the CFA franc zone, I find no consistent results on changes in the pattern of trade.
