Few political issues are more contentious in the United States these days than immigration. Americans’ most persistent fear of today’s immigrants is that they are fundamentally different than newcomers from the past and can never become “real Americans.” Another concern about the foreign-born is that they are a drag on the US economy because, the popular reasoning goes, impoverished newcomers receive more in government services than they contribute in taxes and also depress the wages of native-born workers. Even within academia, there is a widespread belief that recent generations of immigrants and their children differ from newcomers a century ago both in economic attainment and in the extent to which they assimilate into American society.

With Streets of Gold: America’s Untold Story of Immigrant Success, Ran Abramitzky and Leah Boustan hope to influence both popular perceptions and academic debates surrounding these beliefs. Their ambitious, persuasive, thought-provoking book uses a new, enormous dataset to draw several important conclusions: first, that “newcomers today are just as quick to move up the economic ladder as in the past”; second, that recent immigrants “are integrating into American culture just as surely as immigrants did” in the previous generations; and third, that “immigrant success does not come at the expense of US-born workers” (p. 9).

It is the authors’ unique dataset that emboldens them to make such definitive, potentially controversial pronouncements. When economic historians such as Stephan Thernstrom and Joseph Ferrie previously attempted to study these issues, they typically tracked no more than several thousand Americans, and their findings were plagued by selectivity bias. Abramitzky and Boustan, in contrast, have pioneered automated census linking, using algorithms to track millions of individuals from one census record to the next and mining the information therein to track the socio-economic mobility of vast numbers of Americans, native and foreign-born alike.

These data are not perfect. There were thousands of immigrants named Patrick Kelly and Michael Sullivan in the United States, for example, many of whom were not sure exactly when they were born. Others, out of vanity, subtracted years from their ages as they grew older. Because names and ages are key to the authors’ census linking method, it can produce significant numbers of “false positives” which might skew their findings (p. 30). This is primarily the case for census records compiled in 1870 and earlier, when census workers were allowed to estimate the ages of the people they enumerated in their door-to-door rounds. Perhaps understanding this limitation, the authors in Streets of Gold only analyze the socio-economic mobility of immigrants who arrived in American in 1880 or later, making their conclusions much more reliable than they might have been otherwise. The downside of this methodological limitation, however, is that Abramitzky and Boustan compare recent immigrants primarily to immigrants who arrived in the era from 1900 to 1920. Those who wonder how today’s immigrants compare to the Irish who fled the Great Famine or the Germans who emigrated after the Revolutions of 1848 will be disappointed.

One of the most interesting, and persuasive, portions of Streets of Gold is the chapter that compares the intergenerational mobility of immigrants past and present. Despite the appearance a few years back of several small studies that insisted that the children of Latino immigrants are not enjoying as much upward mobility as other foreign-born Americans, Abramtizky and Boustan find with their much larger dataset that these Latino immigrants are no different than European immigrants from the past. “Children of immigrants from Mexico and the Dominican Republic today,” they write, “are just as likely to move up from their parents’ circumstances as were children of poor Swedes and Finns a hundred years ago” (p. 75). In fact, they contend, “children of immigrants” today “are more upwardly mobile than children of the US born” (p. 79).

Like most economists who compare the past to the present, Abramitzky and Boustan sometimes perpetuate immigration stereotypes that historians have long since dispelled. In their efforts to show that today’s immigrants are better off overall than those who came to America in the past, for example, they state that it was once true that Europe, as Emma Lazarus famously put it, sent its “poor, huddled masses” to the United States (p. 49). Yet that was no more the case back then than it is now. Even at the height of the Great Irish Famine of the 1840s and 1850s, those fleeing to the United States were three times more likely to be literate than the overall Irish population and much more likely to be trained in an artisanal trade. Americans of every generation have imagined that recent immigrants were the dregs of their homelands, but this has never actually been the case. In another part of the book (p. 60), the authors convey this fact more clearly.

Another facet of the immigration story that is sometimes difficult for economists to grasp is assimilation. To get at this phenomenon, Abramitzky and Boustan rely on naming patterns (the extent to which the newcomers Americanized their names), intermarriage rates, the extent to which immigrants cluster in ethnic enclaves, and rates of English acquisition. Such measures are sufficient for making the authors’ most important point—that immigrants assimilate “just as quickly today as they did in the past” (p. 110). But while contemporary immigrants do assimilate just as rapidly and just as much as immigrants from the past, that does not mean that adult immigrants in either era assimilated all that much. The foods they ate, the songs they sang, the games they played, and even the languages they spoke at home changed very little over the course of their lives.

Streets of Gold is an important, pathbreaking work based on an enormous and impressive dataset. It ought to be required reading for anyone who wants to weigh in on the debates surrounding immigration policy. Yet it’s a shame that in today’s polarized political climate, the authors’ important findings will probably change very few minds.