An interesting-looking new book has arrived, Exceptional People: How Migration Shaped Our World and Will Define Our Future by Ian Goldin, Geoffrey Cameron and Meera Balarajan. One of the 'puzzles' of economics is why, if free trade in goods and free movement of capital are seen as positive sum phenomena, the free movement of people should be seen as an exception. Yet 'economic migration' is increasingly seen as a problem, rather than an improvement.

The book takes a very long perspective on migration, describing their recurrence since pre-history, and argues that the current wave of movement in this era of globalization is another of those periodic large scale population shifts. Its conclusion appears to be that this is clearly a Good Thing as the main engine of the circulation of ideas and technology. Moreover, the tide cannot be turned but should instead be managed within an international framework. It also looks at some of the problems arising from the current mish-mash of policies and the exploitation of vulnerable people, and also at the benefits of 'brain circulation'. I'll read it with interest. My own experience as a member of the UK's Migration Advisory Committee (whose remit is to provide the economic evidence base to inform government policy decisions) is that a true general equilibrium assessment of migration is difficult indeed.

By chance, as the book arrived, so did an email offering a special collection of free articles about migration from Wiley-Blackwell journals. Let me pick out as most relevant here The Growth and Welfare Effects of World Migration and Emigration in the Long Run: Evidence from Two Global Centuries, the Hatton/Williamson survey article.

The Enlightened Economist will be on holiday for the next few days.