The author considers trade between a flexible-wage America and a rigid-wage Europe. In a benchmark case, a move from autarky to free trade doubles European unemployment. American wages rise to the European level. Entry of the unskilled 'South' to world markets raises European unemployment. Europe's commitment to the high wage wholly insulates America from the shock. Immigration to America raises American income, but lowers European income dollar for dollar, while European unemployment rises. Absent South-North migration of the unskilled from 1970-90, Europe could have maintained the same wage with from one-eighth to one-fourth less unemployment.

Does national market size matter for industrial structure? This has been suggested by theoretical work on "home market" effects. In the present paper, I show that what previously was regarded as an assumption of convenience--transport costs only for the differentiated goods--matters a great deal. In a focal case in which differentiated and homogeneous goods have identical transport costs, the home market effect disappears. This paper discusses available evidence on the relative trade costs for differentiated and homogeneous goods. No compelling argument is found that market size will matter for industrial structure.

I consider trade between a flexible-wage America and a rigid-wage Europe. In a benchmark case, a move from autarky to free trade doubles European unemployment. American wages rise to the European level. Entry of the unskilled "South" to world markets raises European unemployment. Europe's commitment to the high wage wholly insulates America from the shock. Immigration to America raises American income, but lowers European income dollar for dollar, while European unemployment rises. Absent South-North migration of the unskilled from 1970-1990, Europe could have maintained the same wage with from one-eighth to one-fourth less unemployment.