Why has UK net immigration increased?

Since the 1970s Britain has gone from being a country of net emigration to one of net immigration, with a trend increase in the net balance of about 100,000 per year. This paper represents the first attempt comprehensively to model the variations in net migration for British and for foreign citizens, across countries and over time. A simple economic model, which includes the selection effects of differing income distributions at home and abroad, largely accounts for the variations in the data. The results suggest that improved economic performance in the UK relative to overseas has tended to increase immigration. But a more important influence, especially on the reduced out-migration of British citizens, has been growing UK inequality. By contrast, shifts in immigration policies at home and abroad seem to have been relatively unimportant