Is Opposition to Immigration Primarily Economic or Cultural?

It's clear that there is a considerable hostility to immigration, both in the United States and across much of Europe. Is that opposition rooted primarily in economic factors or in cultural factors? What kind of evidence could help answer the question?

One approach is to look at whether anti-immigrant attitudes are more common among occupations more threatened by immigrant competition or in local areas that have received more immigrants.  If so, this would support an economic explanation for anti-immigrant sentiment. Another approach is the "survey experiment," which involves doing a survey with several different versions that differ in  what questions are asked, and thus seeing what factors are shaping people's attitudes. Both approaches suggest that that cultural factors than economic factors in anti-immigrant sentiment.

For a sampling of the evidence on this point, I'll draw upon some comments in a couple of papers in the Fall 2019 issue of the Journal of Economic Perspectives: "The Surge of Economic Nationalism in Western Europe," by Italo Colantone and Piero Stanig (pp. 128-51) and "Economic Insecurity and the Causes of Populism, Reconsidered, by Yotam Margalit (pp. 152-70). 

For example, Colantone and Stanig looked at areas that had received more immigrants and found: 

Public opinion research consistently finds that direct competition with immigrants on the labor market is not an important predictor of anti-immigration sentiments. Instead, anti-immigrant views are mostly driven by generalized fears of potential economic or social harm caused by immigration, perceived as a threat to national culture (Hainmueller and Hopkins 2014). ... 

Empirical evidence suggests that economic hardship of different origin may be a more important predictor of anti-immigration sentiments than the actual presence of immigrants in a region. As one vivid example, immigration was one of the single most important issues motivating Leave voters in the Brexit referendum of 2016 (Ashcroft 2016; Ipsos MORI 2016). Yet there is no robust evidence of higher Leave vote shares in regions where a larger fraction of the population is foreign born, or where relatively more immigrants arrived in the years prior to the referendum (Colantone and Stanig 2018a). Consistently, our own empirical evidence shows that negative attitudes about immigration at the individual level are driven not by the share of foreign-born population in the region of residence, nor by the recent arrival rates of immigrants. Rather, what seems to explain nativist attitudes is contextual economic distress—for instance, driven by the exposure to the Chinese import shock (Colantone and Stanig 2018a). Economic distress also seems to drive more cultural concerns about immigration, such as the belief that immigrants do not make a positive contribution to the national cultural life (Colantone and Stanig 2018a, b). In a situation of poor economic performance, it can be easy and politically rewarding to blame immigrants, even when the underlying economic grievances have very different origins, as in the case of globalization. 

Margolit found that opposition to immigration doesn't seem linked with whether one works in an occupation more likely to be disrupted by immigrant labor:

Furthermore, my collaborators and I find that workers employed in very different segments of the labor market, such as meat-packing, education, and finance—differing in terms of skill specificity, penetration by foreign labor, and value added per worker—share remarkably similar preferences in terms of the skill profile of the immigrants they are willing (or not) to accept (Hainmueller, Hiscox, and Margalit 2015). This finding does not sit well with a prediction that natives will be more opposed to immigrants with skill levels similar their own, or indeed with any model that predicts that different segments of native workers will have different preferences regarding the desired type of immigrants.

Margolit also describes "survey experiments," where several slightly different surveys are given, and then the results can be compared to get a sense of what is affecting people's beliefs--especially about issues like bias against immigrants of different ethnic or cultural background. Here's an example: 

For example, a survey experiment in the United Kingdom varied the information it provided to participants about the skill mix of immigrants coming into the country, their region of origin, and the impact of immigration numbers on the long-term share of white Britons. The study finds that even when controlling for the information about skill mix and region of origin, the very mention of the immigrants’ impact on the share of white Britons almost halves support for current immigration levels (reducing it by 17–22 percentage points to about 20 percent of the public) (Kaufmann 2018). Experiments conducted in the United States find a similar effect, in which prompting (or reminding) white Americans about the impending racial shift and future loss of their majority status magnifies their racial bias, particularly toward Hispanics, and increases support for restrictive immigration policies (Craig and Richeson 2014; Major, Blodorn, and Blascovich 2018).

Another kind of survey experiment is a "list experiment," which Margolit describes in this way: 

In a study using this method, Janus (2010) randomly divided a national sample of US non-Hispanic whites into two groups and asked them to read a list of several statements. After reading the list, respondents in both groups were asked to report the total number of statements they “oppose or are against,” without having to report their view on each specific statement. For the control group, the list included three statements on issues on which concerns with social desirability are unlikely to be a problem, such as whether or not they oppose “Professional athletes making millions of dollars per year.” For the treatment group, the list contained the same three nonsensitive statements, but with an addition of a fourth statement: “Cutting off immigration to the United States.” In this experiment, the difference in the mean number of statements reported by participants in the control group (1.77) and the mean number reported by participants in the treatment group (2.16) is attributable only to the additional sensitive item and to sampling error.

In doing surveys about attitudes concerning immigration, one of the strongest results is that those with less education are much more likely to be opposed to immigration, while those with more education are likely to favor immigration.  The key point here is that those with high education levels favor more immigration of those with both high and low skill levels, which presumably includes support for immigration of those who would be competing with them for jobs. Conversely, those with low education levels tend to oppose immigration of those with both high and low skill levels, which means they oppose immigration both of those who might be competing with them for jobs and also those who are unlikely to be competing with them. This pattern suggests cultural attitudes about immigration correlated with higher and lower levels of education are driving the results.

The message that current hostility to immigration is primarily cultural is consistent with recent research on US opposition to immigration a century ago. Marco Tabellini published "Gifts of the Immigrants, Woes of the Natives: Lessons from the Age of Mass Migration," in the Review of Economic Studies, which is waiting in line in the form of corrected proof pages to be published (as of May 6, 2019).  Here's the abstract of Tabellini's article:

In this article, I jointly investigate the political and the economic effects of immigration, and study the causes of anti-immigrant sentiments. I exploit exogenous variation in European immigration to U.S. cities between 1910 and 1930 induced by World War I and the Immigration Acts of the 1920s, and instrument immigrants’ location decision relying on pre-existing settlement patterns. I find that immigration triggered hostile political reactions, such as the election of more conservative legislators, higher support for anti-immigration legislation, and lower redistribution. Exploring the causes of natives’ backlash, I document that immigration increased natives’ employment, spurred industrial production, and did not generate losses even among natives working in highly exposed sectors. These findings suggest that opposition to immigration was unlikely to have economic roots. Instead, I provide evidence that natives’ political discontent was increasing in the cultural differences between immigrants and natives. Results in this article indicate that, even when diversity is economically beneficial, it may nonetheless be socially hard to manage.

In the United States, as in many other countries, immigration is a relatively small factor in its effect on either levels of wages or inequality of wages. (For discussion of the US situation in particular. see  Giovanni Peri, "Immigrants, Productivity, and Labor Markets," Journal of Economic Perspectives, Fall 2016, 30:4, pp. 3-30.) The enormous political energy surrounding immigration issues grows from non-economic roots.