The study of immigration in sociology has generally declined in importance along with the plummeting political and social stature of immigrants. Studying immigration is uncool, because it’s demography. And, demography is uncool because it’s boring and all of the cool people did poorly in it because they can’t count or pay attention for very long. So, it may be ok to study immigrant culture, something different and unique and other. But May All The Jesuses Weep if one take to explaining social change with reference to simple demographic processes like migration.
Rachel McCleary was kind enough to include a chapter on religion and immigration in her Oxford Handbook of the Economics of Religion which was just published. Above are some odds ratios from that paper comparing the nation of origin to immigrants from that nation. One of the things that I show (following up on some things done in Alanezi and Sherkat 2008), is that immigrants to the US from European nations are far more religious than people who stay in the homeland. Germans are more than twice as likely to reject a religious identification than are first or second generation Germans immigrants to the United States, and this is true for immigrants from MANY nations. While a substantial fraction of Dutch, Germans, Russians, Chinese, Japanese, Belgians, Czechs, Lithuanians, Brits, and French hold no religious identification, first and second generation US immigrants from these nations are much more likely to have an identification than are their former compatriots. In contrast, immigrants to the US from highly religious non-Christians nations (or even predominately Catholic countries) are less likely to be religious than those in their home nations.
Why is the United States so religious and Europe is not? Well, for one thing, you motherfuckers have been shipping your god-damned religious nutcases to the United States for more than 400 years. Thanks, assholes.