It's becoming increasingly difficult to be opposed to significant immigration for economic reasons. One of the more sophisticated arguments for restricting migration–proponents include Paul Collier, in Exodus: Immigration and Multiculturalism in the 21st Century, and George J. Borjas in Immigration Economics–concerns the socio-political baggage that immigrants bring with them; institutions, characteristics, and social norms which might even have had some bearing on the poverty of their countries of origin. There’s a substantial literature to support the claim that institutions like secure property rights and the rule of law are by far the most important guarantors of long term prosperity and growth. If it were true that high levels of immigration could serve to undermine these institutions, (as Borjas hypothesises) significantly mitigating the vast welfare gains some predict immigration will bring, those who support very high levels of immigration might well reevaluate their position.
The newly updated version of a Cato Institute working paper, soon to be published in Public Choice, goes some way to looking at these claims empirically. They use data from the Economic Freedom of the World Annual Report to examine the effects of migration on the institutions such as property rights. The main finding of their analysis is that countries with a larger percentage of immigrants in their population in 1990 had a higher level of economic freedom in 2011.
Indeed, Clark et al. conclude:
Regardless of the immigration measure used or the precise regression specification, we have not found a single instance in which immigration is associated with less economic freedom. It does not appear that immigrants are bringing the poor economic freedom records of their home countries abroad with them.
and
Overall, we find some evidence that larger immigrant population shares (or inflows) yield positive impacts on institutional quality. At a minimum, our results indicate that no negative impact on economic freedom is associated with more immigration.
As the evidence around the economic case against immigration is weakened (I could have also blogged today about a recent CReAM discussion paper which concludes that low-skilled immigration to Denmark pushed up native wages, employment, and occupational mobility), we might wonder whether people have other reasons for opposing it.