This paper deals with the effects of European integration in the EC an
d EFTA on economic growth. Base regressions suggest that EC and EFTA m
emberships do in fact have a positive and significant effect on econom
ic growth, and that there: is no significant difference between EC and
EFTA membership. This result is not completely robust with respect to
changes in the set of control variables and to measurement errors. No
netheless, the results suggest that regional integration may not only
affect resource allocation, but also long-run growth rates. This concl
usion is strengthened by the fact that we obtain similar results when
we use panel data for a sample of OECD countries. A number of tests ar
e also conducted to ascertain that the EC/EFTA variable is not primari
ly a proxy for the effect of economic development. In addition, we exp
lore possible indirect effects of regional integration.