At the end of the 20th century nearly all developed nations have become countries of immigration, absorbing growing numbers of immigrants not only from developed regions, byt increasingly from developing nations of the Third World. Although international migration has come to play a central role...

This paper analyses the border effect in Spain using a unique dataset on intranational trade flows over the period 1995-98. The results indicate that, after controlling for market size and distance, Spanish regions trade around 22 times more with the rest of Spain than they do with OECD...