CONVENTIONAL wisdom holds that the surge in migration to Europe since 2015 has set off a backlash in anti-immigrant sentiment. Opinion polls, however, do not support this link. In November 2014 Eurobarometer began asking citizens of EU countries about their feelings towards immigrants. Since then, the overall share of people who view arrivals from outside the bloc positively has risen from 35% to 41%. Different regions of the EU, however, have been pulling in opposite directions. Western and southern European countries have generally become friendlier to foreigners, whereas northern and eastern ones have grown more hostile.

What explains this continental divide? The answer is not the number of asylum-seekers that the countries have received. Sweden, Denmark and Poland have all become much less welcoming to immigrants. Yet they experienced only small changes in refugee inflows, when comparing 2015 and 2016 to the previous two-year period. Overall, there is no statistically significant correlation between increasing tallies of asylum applications and rising rates of xenophobia.

However, there does seem to be a link between a country’s change in anti-immigrant sentiment and its racial diversity. One thing that Scandinavia and Visegrad have in common is a historically low share of people who are not white. Measuring this is difficult, since countries collect information about ethnicity in different ways. France forbids the collection of data about race altogether, lest it be used to discriminate. The best continental estimates come from the European Social Survey (ESS), which began asking respondents about their ancestry in 2014. These can be used to approximate the share of people in each country that have some non-Western ancestry (i.e. from outside Europe, North America or Australasia).