Interview: Leah Boustan, economist

In which we talk all about immigration

Immigration is obviously one of the most important and most contentious issues of our time. The sheer amount of confusion, misconception, and misinformation is just staggering. So when I want to know the hard facts on the immigration issue, I go to Princeton economist Leah Boustan.

Boustan’s research covers far more than immigration — she’s incredibly versatile, covering labor economics, urban economics, economic history, and more. But recently, her research on immigration has garnered a lot of (well-deserved) attention. In a series of recent papers, she and her various co-authors showed that 1920s immigration restrictions hurt native-born American workers, that immigrant groups give their kids less foreign-sounding names over time, that immigrants do better economically when they move out of ethnic enclaves, and that the children of poor immigrants tend to be extremely upwardly mobile.

In her new book with Ran Abramitzky, Streets of Gold: America's Untold Story of Immigrant Success, Boustan draws from her own research and others’ to weave a nuanced yet compelling story of how immigrants fare in the United States — and how little this has changed between the early 20th century and the early 21st. It’s a great book, and I highly recommend it to everyone.

In this interview, I ask Leah about her book, and about the immigration issue in general. Enjoy!

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N.S.: I've been following your work for years, and you're my favorite economist of immigration. How did you first become interested in that topic?

L.B.: First, thank you! That is so kind to say and I have appreciated all of your engagement with our work through the years. I will always associate the “before times” (immediately pre-Covid) with being able to meet in person at the ASSA conference in Jan 2020.

So, how did I become interested in immigration? Well, my first book was on the black migration from the rural South to industrial cities in the North and West (the Great Black Migration). I got interested in this topic when reading William Julius Wilson's The Truly Disadvantaged and encountering a paragraph with what seemed like an aside, but it really is a gem of an idea. Wilson said something like "ironically, European immigrants benefited from the closing of the US border in the 1920s, but black migrants faced a lot of competition because you can't close the Mason-Dixon line." (This is a paraphrase!). I thought to myself - wow - I always knew about white ethnic communities in US cities, but I never really thought of the black community as a *migrant* community. So what if we - as economists - really study African-American history as migrant history? My first book was called Competition in the Promised Land, which picks up on this idea.

It was pretty natural after that to turn my attention to studying European immigrants in the late 19th and early 20th centuries. Sociologists like Wilson and like Stanley Lieberson explicitly or implicitly compare white ethnic progress with African American progress. So, after working for some time on black migrants, I wanted to learn more about European immigrants as well.

N.S.: What do you think are the biggest popular misconceptions about immigration in America today?

L.B.: To start off with, Americans vastly overestimate how many immigrants are in the country today. According to a survey conducted by Stefanie Stantcheva and her co-authors, Americans guess that 36% of the country is born abroad, whereas the real number is 14%. So, this misconception gives rise to fears that we are in an "immigration crisis" or that we have a "flood" of immigrants coming to our shores. In reality, the immigrant share of the population today (14%) only just reached the same level as it was during the Ellis Island period for over 50 years!

After this, I would say that the second biggest misconception is that immigrants nowadays are faring more poorly in the economy and are less likely to become American than immigrants 100 years ago. We look back to the Ellis Island period with nostalgia, both on the right and the left. Even MAGA-types like Rush Limbaugh have nice things to say about immigrants who arrived from Europe in the last century. But there is a perception that because immigrants today come from all over the world -- particularly from Asia and Latin America, and including from some very poor sending countries -- that these immigrants will not be able to climb the ladder economically and that, culturally, they are too different to ever fit in.

N.S.: How do we measure cultural "fitting in"? Are there deeper metrics of cultural integration beyond simple things like language skills? And if so, what do those metrics tell us?

L.B. We are economists, so the first work we did on immigration was focused on economic outcomes like earnings and occupations. But, voters often care more deeply about cultural issues - both in the past and today. So, we realized that we wanted to try to measure 'fitting in' or cultural assimilation using as many metrics as we could find. We looked at learning English, of course, but also who immigrants marry, whether immigrants live in an enclave neighborhood or a more integrated area, and - one of our favorite measures - the names that immigrant parents choose for their children. These are all measures that can be gathered for immigrants today and 100 years ago; there are other metrics for today that don't exist for the past -- like 'do immigrants describe themselves as patriotic' (answer is: they do).

What we learned is that immigrants take steps to 'fit in' just as much today as they did in the past. So, for example, we can look at the names that immigrant parents choose for their kids. Both in the past and today, immigrants choose less American-sounding names for their kids when they first arrive in the US, but they start to converge toward the names that US-born parents pick for their kids as they spend more time in the country. Immigrants never completely close this 'naming gap' but they move pretty far in that direction, both then and now. (One interesting element of this measure is how to figure out what names are 'American-sounding.' We just let the data tell us by counting the number of people with each first name who were born abroad or born in the US. Names like Eric and Kurt used to be very 'foreign-sounding' in the past but they are 'American-sounding' today, so these fads change).

N.S.: Gotcha. So let's talk about Mexican immigrants specifically, because this is a group that you focus a lot on in your new book. There's a long history of American pundits and politicians freaking out over Mexican immigration, from Samuel Huntington to California's Proposition 187 to Donald Trump's comments in the 2016 primary. And on the other side there's a pretty well-known book, "Generations of Exclusion", by Edward Telles and Vilma Ortiz, that alleges that Mexican Americans have been excluded from full participation in the American economy and American society. And yet in your book, you say no, this is all wrong -- Mexicans do fine economically and rapidly integrate into American society as well. Can you expand on that a bit, and tell us why all those worries were misplaced?

L.B.: We find that Mexican immigrants and their children achieve a substantial amount of integration, both economically and culturally. First, on the economic side, we compare the children of Mexican-born parents who were raised at the 25th percentile of the income distribution -- that's like two parents working full time, both earning in the minimum wage -- to the children of US-born parents or parents from other countries of origin. The children of Mexican parents do pretty well! Even though they were raised at the 25th percentile in childhood, they reach the 50th percentile in adulthood on average. Compare that to the children of US-born parents raised at the same point, who only reach the 46th percentile. Of course, children of other immigrant backgrounds do even better, but the children from Mexican households are experiencing a lot of upward mobility. I should point out that the picture does not look quite as hopeful (but still looks pretty good, to my eyes) if we compare the average child of Mexican parents to the average child of US-born parents. Because the average children of Mexican parents grow up in poorer households, they do start with some disadvantages, so the children of Mexican parents do not completely catch up with the children of US-born parents on average. But, their earnings gap is a lot smaller than what their parents experienced, so the second generation is doing substantially better than the first -- and that's important progress.

On the cultural side, we already talked about some of the metrics we use to assess whether immigrants are fitting in. Some people worry these days that Mexican immigrants hold themselves apart - that they are more likely to live in Spanish-speaking enclaves, etc. But we find that Mexican immigrants are actually the group that experiences the fastest assimilation, as measured by the names that they pick for their children. So, Mexican immigrants are certainly trying to become American to the same degree (if not more!) than other groups.

N.S.: So were researchers like Tellez and Ortiz simply using worse data than what's available now, or have opportunities improved for Mexican Americans since they wrote their book?

L.B. It could be a little bit of both. The Tellez and Ortiz study is really an amazing feat - they recovered a set of detailed interviews with Mexican immigrants living in Los Angeles or San Antonio in the 1960s from earlier scholarship and were able to locate a number of their children a generation later.  But, their sample is quite specific: Mexican immigrants who were already living in the US in the 1960s at the time of the Bracero program in two specific cities (Los Angeles and San Antonio). Our study focuses on immigrants living in the US in a later period (the 1980s) all over the country. One of the main changes for Mexican immigrants in the 1980s and 1990s is that they settled in larger numbers away from "gateway" communities. Mexican immigrants also diversified their employment, away from agriculture to a wide range of occupations and industries. So, our data is different -- with much larger samples that are more geographically distributed and closer to the modern period. But, it's also possible that the opportunities for advancement have also improved from growing up in the 1960s to growing up in the 1980s, and that could also explain why our findings are different.

N.S.: Gotcha. OK, let's talk a little bit about economic success in general. You and your co-authors found that the kids of immigrants who are born at the 25th percentile of income -- in other words, poor or working-class kids -- tend to have greater economic success than the kids of American citizens of similar income levels. For some groups, like the kids of Honduran and British immigrants, the difference is only modest, but for others, like the kids of Indian and Chinese immigrants, the differences are enormous. Why do poor and working-class kids of immigrants do so much better than their American counterparts, and what are some of the reasons for the national differences?

L.B. First, I wanted to mention that the pattern that you describe, whereby the kids of poor and working-class immigrants do better than their American counterparts, is true both today and in the past. The children of poor Irish or Italian immigrant parents outperformed the children of poor US-born parents in the early 20th century; the same is true of the children of immigrants today. 

We are able to delve into the reasons for this immigrant advantage in the past in great detail, and we find that the single most important factor is geography. Immigrants tended to settle in dynamic cities that provided opportunities both for themselves and for their kids. So, in the past, this meant avoiding Southern states, which were primarily agricultural and cotton-growing at the time, and - outside of the South - moving to cities more than to rural areas. If you think about it, it makes sense: immigrants have already left home, often in pursuit of economic opportunity, so once they move to the US they are more willing to go where the opportunities are. 

Geography still matters a lot today, but not as much as in the past. Instead, we suspect that educational differences between groups matter today. Think about a Chinese or Indian immigrant who doesn't earn very much, say working in a restaurant or a hotel or in childcare. In some cases, the immigrant him or herself arrived in the US with an education - even a college degree - but has a hard time finding work in their chosen profession. Despite the fact that these immigrant families do not have many financial resources, they can pass along educational advantages to their children.

N.S.: Right. So with regards to those national differences in upward mobility. I was wondering how much of it is due to differences in how selective our system is toward different countries. In a 2017 paper, the economist Ed Lazear showed that most of these differences in outcomes can be explained by selectivity -- the more populous a country is, and the smaller number of immigrants we take from that country, the more economically successful immigrants from that country tend to be. (In fact, you may not remember this, but it was at a conference session for that paper that you and I first met in person!) So this theory seems like it would predict why 2nd-generation Chinese and Indian immigrants are even more upwardly mobile than other immigrant groups -- because China and India are such enormous countries that we end up getting the "cream of the crop". You didn't really mention this idea in your book, but do you think this is what's going on?

L.B.: It might be -- but it seems more plausible to me that Lazear's paper would explain where the typical immigrant parent ends up in the income distribution and not how the children of immigrant parents raised below the median would fare. So, for example, Mexican immigrants earn less than the US-born on average and Chinese immigrants earn more than the US-born. These two sending countries are relatively similar in GDP per capita (between $8000 and $10,000 per capita), so the high earnings of Chinese immigrants can be explained by more positive selection, in the sense that Chinese immigrants are among the most educated and wealthiest from their home country, whereas Mexican immigrants represent the country's typical resident. In that case, children of Chinese-born parents are more likely to start out close to the top (maybe at the 75th percentile), whereas the children of Mexican-born parents are more likely to start out close to the bottom (say at the 25th percentile). But his theory has less to say about what would happen to two kids who started at the 25th percentile.

N.S.: Do we know anything about how 2nd-generation upward mobility interacts with parental education or other parent characteristics? Controlling for income, do kids of highly educated immigrants show more upward mobility than kids of less-educated immigrants?

L.B. We weren't able to delve into this question for the contemporary period because our data was based on income tax records (courtesy of the Opportunity Insights lab at Harvard). We were only granted access to aggregate statistics by parental income and parent's country of birth, so we didn't have "micro" data (records at the individual level) that would allow us to control for other information like education or occupation. 

In the historical periods we consider, we were able to look at the role of education in explaining the upward mobility of the children of immigrants. For kids who were in childhood in 1910 and then observed in the labor market in 1940, we find that the children of immigrants have lower levels of education than otherwise similar children of US-born parents, but yet they earn more. Why is that? Again, it has to do with the role of geography. Immigrants and their children lived in more dynamic locations (in cities, outside of the South) that offered opportunities to earn more, even for workers with fewer years of schooling.

N.S.: One reason I ask is that the question of selective immigration has been brought up a lot in policy debates. Some people (like me) would like to add new routes for skilled immigration, such as a points-based system and a regional visa sponsorship system like the ones used in Canada (in addition to adding more refugees and other immigrants). On the political right, some have proposed shifting immigration away from family reunification and toward skills-based admission.  In your book, however, you downplay the importance of selectivity. Why?

L.B. We are very on board with the idea of adding new routes for high-skilled immigration or expanding the number of slots available under current programs (e.g., the H-1B visa, which hasn't increased in number since the 1990s!). But, we get worried when we hear proposals to keep the number of slots the same -- or even reduce the number of slots available -- and shift toward skilled immigration (like the 2017 Raise Act proposed during the Trump Administration). Immigrants arrive these days with a very "bimodal" set of skills. That is, some immigrants have a lot of education, beyond a BA, PhDs in highly technical fields. And other immigrants never even had the chance to start high school. Immigrants with low levels of education are performing vital services right now, in agriculture, child and elder care, restaurant work, etc. Some people say "sure, we need those workers now but we don't want them bringing their families because we don't want to import a permanent underclass." And, with the data we uncovered, we are trying to say: we don't need to worry that the children of working-class immigrants will not rise, because they move up the ladder very quickly.

N.S.: But even the immigrants people (somewhat disparagingly) call "low-skilled" are actually pretty selected, right? It takes a lot of bravery, motivation, and resourcefulness to pick up and move to a new country, especially without much money or connections or language skills. 

L.B. I’m guessing that you are right, although we have not been able to directly study the personality traits associated with becoming a migrant ourselves. We know that immigrants in the past from Europe tended to be from poorer families (the “tired poor huddled masses” from the Emma Lazarus poem turns out to be right!) and that immigrants today from around the world tend to be from wealthier backgrounds or to have more education. So, at least on what we can measure, the selectivity of immigrants has changed. But, on the elements of personality that we have not been able to measure (motivation, willingness to take risks), it could be that selection has remained the same. 

N.S.: So if you were in charge of U.S. immigration policy right now, what would be your three top priorities? 

L.B. First, more than any specific policy, I think that politicians and policy makers have to be more vocal about the successes of immigrants and their contributions to the US economy and US society. The classic idea of the US as a “Nation of Immigrants” was a concept promoted by President Kennedy in the early 1960s, that immigrants built the country and that they served patriotically in WWII. These days, I mostly see politicians playing defense. Someone accuses the administration of being “open borders” or turning a blind eye to the “immigration crisis” and then the administration responds. But what about highlighting all of the incredibly inspiring stories, and helping to change the narrative?

In terms of policy, we see two main priorities emerging from the research: providing a pathway to citizenship for undocumented immigrants, and expanding opportunities for entry for high-skilled immigrants (without taking slots away from other immigrant groups! So, that would mean expanding entry slots by a reasonable amount to allow for more high-skilled entry).

In our book, we were able to follow the children of immigrants born in the early 1980s who are now mid-career. These kids may have benefited from the 1986 Immigration Reform and Control Act — the amnesty program passed under President Reagan — that allowed many undocumented immigrants to enter a path to citizenship. What will we see when we are able to follow children born in the 2000s? Will the successes that we measure still be present for undocumented children or for children who were raised in households with undocumented parents? We’d like to get more systematic information about this, but we would need to wait a bit longer for these children to reach middle age. In the meantime, sociologists have highlighted a wide set of barriers that these children now face in accessing higher education and jobs in the formal labor market. These barriers are entirely policy-driven. We erected these barriers as a society, and we can take them away.

On high-skilled immigration: we have around the same number of slots now as we did in the early 1990s, through H-1B visas and other entry mechanisms. High-skilled immigrants earn a lot and contribute a lot right off the bat, their children do incredibly well too, and they contribute to innovation and entrepreneurship that open up jobs for others. So, why are we capping entry at such low levels and losing out to our competitors?

N.S.: Gotcha. Well, one last question: What are you working on next? Any projects in the hopper that we should be getting excited about?

L.B. Well, Ran and I are continuing to make headway on understanding immigration, then and now. We have been working lately on the probability of incarceration for immigrants and the children of immigrants historically (spoiler alert: it’s lower than for the US-born!). There is good data on this topic already for the modern period showing that immigrants are much less likely than the US-born to be arrested or incarcerated, but the data for the past has been more patchwork so we are filling that in. 

I’m also working on a variety of topics in the mid-twentieth century, including the role of the Cold War and the Red Scare in discouraging social movements and progressive legislation, and the effect of the early “computerized factory” on the labor market and on productivity. American history continues to be endlessly fascinating to me!

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