MANY of those who voted to stay in the European Union in Britain’s recent referendum play up the lack of contact between Leavers and migrants. Although immigration featured heavily in the campaign, areas with the highest levels of immigration—notably London—were often among those most likely to vote to Remain (see chart 1 above). To mint-tea-sipping metropolitans, it seems absurd that people who live in areas with comparatively low numbers of Poles or Romanians should have been so keen to put a stop to migration.

But that is not the full picture. Consider the percentage-change in migrant numbers, rather than the total headcount, and the opposite pattern emerges (chart 2). Where foreign-born populations increased by more than 200% between 2001 and 2014, a Leave vote followed in 94% of cases. The proportion of migrants may be relatively low in Leave strongholds such as Boston, in Lincolnshire (where 15.4% of the population are foreign-born). But it has grown precipitously in a short period of time (by 479%, in Boston’s case). High levels of immigration don’t seem to bother Britons; high rates of change do.