Hillman and Weiss in chapter 4 effectively survey a large number of ideas embodied in the recent migration literature. Their survey succeeds in providing both ‘the big picture’ and vivid examples of these ideas, and it is therefore a useful and enjoyable read.

The survey can be broadly split into three parts, each discussing a separate question. The first part – inclusive of sections 1 and 2 – is about the causes of asymmetries in trade and migration policies. It is argued that cultural differences play a major role in determining such policy asymmetries. The second part (section 3) draws on theories of migration where cultural factors play a role, unlike the standard theory based on wage differentials. The third part of the survey (section 4) concerns the endogenous determination of immigration policies as a response to cultural heterogeneity.

The survey as a whole revolves around the idea that cultural heterogeneity is an important determinant of the policy attitudes of governments. This is the main point I wish to take up in my discussion. While I agree that taking heterogeneity seriously is important, I am not entirely convinced that cultural differences across communities can go a long way in explaining migration policies.

Why should cultural heterogeneity matter for migration policies? The authors' starting point is that factor movements are not interchangeable. Capital inflows, as well as the imports of goods, do not usually imply the mixing up of people, unlike migration. Then, if natives dislike having too much variety of people around, liberalising labour flows is not the same as liberalising flows of capital or goods.