Pick and mix

摘要

When it comes to managing immigration, there is nothing like distance. Canada and New Zealand are a long way from the world's poor, and can therefore be finicky about who they let in. Britain is not so isolated, although (in this as in some other respects) it thinks it is. On March 7th, the government unveiled a system for screening would-be settlers that, it promises, will be the most precise in Europe.