The economics of open borders
A colleague recently sent me a paper on the economics of open borders, by John Kennan, which I hadn’t known of before, though it came out in 2013.
Kennan’s conclusion is striking
Liberal immigration policies are politically unpopular. To a large extent, this is because the beneficiaries of these policies are not allowed to vote. It is also true, however, that the enormous benefits associated with open borders have not received much attention in the economics literature.20 Economists are generally enthusiastic about free trade. But if free movement of goods is important, then surely free movement of people is even more important.
One conclusion of this paper is that open borders could yield huge welfare gains: more than $10,000 a year for a randomly selected worker from a less-developed country (including non-migrants). Another is that these gains are associated with a relatively small reduction in the real wage in developed countries, and even this effect disappears as the capital–labor ratio adjusts over time; indeed if immigration restrictions are relaxed gradually, allowing time for investment in physical capital to keep pace, there is no implied reduction in real wages.
So, is Kennan right about the benefits of open borders? And if so, is there a way of transferring some of those benefits to already-resident wage earners who would otherwise lose, or at least not gain, from expanded migration?
On the first question, I’ll offer a bold Maybe. Kennan’s core assumption is that immigrant workers with a given level of education and (I think) experience will have the same productivity as already resident workers. So a move from a low productivity country to a high productivity country produces a big increase in their effective labor capacity. That benefits those workers, but also produces a shift in global income from labor to capital since the supply of labor has increased.
There’s room to debate this assumption, and there are special cases where it clearly doesn’t apply, such as that of professionals whose qualifications aren’t recognised in their new country. But Kennan makes a good case that it isn’t far from the truth.
Moreover, in a world where more than a billion people travel internationally each year, it’s inevitable that vast numbers of people are going to have close relationships of all kinds with citizens of other countries. Restrictions on movements across borders impose costs on all those people ranging from minor to calamitous.
Supposing that Kennan is right about the economics, what can be done to spread the benefits of open (or less tightly closed) borders more broadly and thereby, potentially, get increased political support. Since owners of capital benefit from open borders, an obvious possibility would be to increase the rate of tax on capital income and redistribute the income to labor. That seems neat enough in the abstract, but there’s no obvious (to me) way of putting it together as a political package.
The other way to spread the gains would be to tax, or otherwise capture, some of the benefits gained by immigrant workers. For example, new immigrants could be obligated to make a contribution, say through a tax surcharge, to a fund representing their share of the existing infrastructure of the destination country. Again, it seems neat enough in the abstract, but there are obvious difficulties. In particular, migrants who could have entered anyway would be significantly worse off.
Still, it seems unlikely that support for the migration policy status quo, let alone an expansion of existing flows, will be an adequate response to the rise of rightwing identity politics (what I’ve previously called tribalism), in which opposition to migration is a central feature. The more people who see freer movement as benefitting them and their families, the better will be the chances of mobilising support for a diverse and tolerant society.