Two weeks ago, I reflected on some of the evidence I had reviewed on Catalán nationalism. I used it to support the argument that freer societies have a higher probability of cosmopolitanism, because their populations are likely to be more diverse. I also noted, although only in passing, that Cataluña has, historically, been one of modern Spain’s wealthier regions.
Alberto Alesina, Johann Harnoss, and Hillel Rapoport have published a paper on a related topic, immigrant diversity and economic growth. They review their findings in a recent Vox article, “Immigration, Diversity, and Economic Prosperity.” The main take away is that there is an empirical relationship between greater diversity and positive economic growth (although, they clarify later that optimal diversity is not what me might call perfect diversity — there are costs, too). But, do prosperous countries attract a more diverse population of immigrants, or does greater diversity amongst immigrants promote greater economic growth? In what way does causality run? They suggest causality probably goes both ways, but they do find,
…substantial evidence of causality going from diversity of skilled immigration to productivity of the receiving country.
One theory the authors offer is that immigrants from different countries will tend to bring in different perspectives and ideas, given variations in culture, education, experiences, et cetera. This greater heterogeneity in intellectual capital, which can be exploited through a division of labor, will tend to increase productivity. They also briefly review some of the empirical literature (pp. 4–6 of the NBER paper).
They mention that some costs of greater diversity include increased difficulty of communication (because diverse people speak different languages), social conflict, et cetera. These are all relevant costs, but I wonder if there’s an economies of scale type relationship. That is, over time, costs should fall as people integrate and begin to socially accept the diversity. For example, the U.S. has seen a lot of racial tension throughout the 20th century, but ,while there is still plenty of racism, I’d like to think that most of us who live amongst diverse populations have a culture of acceptance. In Spain, there’s tension because large scale immigration from abroad is a relatively recent phenomenon, but hopefully much of it should subside over the long-run as this new diversity becomes reflected in the country’s culture. That’s how I envision it, at least.