European countries are introducing increasing barriers to immigration. With the gradual abolition of border controls within Western Europe, a uniform agreement is needed such as outlined in the Schengen accord which makes full allowance for genuine refugees. The pressure to accept immigrants from Eastern Europe will be very strong.

The basic theory is presented through a parable, showing that immigrants do not lower the incomes of natives, on balance. The main empirical issues are also discussed: contrary to popular belief, immigrants into the U.S. and Canada, and almost surely into Europe as well, pay more in taxes than they receive in welfare transfers, thereby enriching natives. Also, an extensive body of recent research finds that immigration does not increase native unemployment.