In today's America, both anti-immigrant and pro-immigrant rhetoric are parroted and retweeted with little attention paid to the facts. And facts are exactly what Ran Abramitzky and Leah Boustan's new book, Streets of Gold, brings to the table. Drawing on insights from over a decade of research, Abramitzky and Boustan set out to correct myths about immigration that have stubbornly persisted over time. During the Age of Mass Migration, did Europeans arrive in rags and quickly work their way to riches? Are today's migrants assimilating at a slower pace than those in the past? Do migrant outcomes persist across generations? Rather than accepting anecdotes at face value, Abramitzky and Boustan turn to the data to measure outcomes for the average migrant. With these data, which span two centuries, one can further understand other important questions, such as the impact of immigration on the economy and whether the impact has changed over time.

While the book focuses on dispelling myths and establishing facts, it is not a dry reci-tation of results from their published research. Abramitzky and Boustan instead create a rich narrative that weaves empirical findings with personal stories from their own and others' lives. They include the origin story of their co-authorship, as well as the initial fits and starts when working on their path-breaking method of linking censuses. They often draw on a qualitative survey they ran, especially for the book, which collected stories about people's immigration backgrounds. And the book is clearly intended for an interdisciplinary audience rather than just economists. In addition to numerous refer-ences to historians and sociologists, Abramitzky and Boustan discuss their co-authored research with computational linguists on immigrant speech patterns and the tone of congressional speeches. In general, the writing is excellent, and anyone interested in data and history could read the book with ease.

One may mistake from the book's title that Abramitzky and Boustan present a purely sanguine view of immigration, but the text describes a more complex reality. Indeed, the book's title comes from a quote that is displayed at Ellis Island, where an immigrant expected that America's streets would be "paved with gold." This optimism was soon shattered: "when I got here, I found out three things: first, the streets weren't paved with gold, second, they weren't paved at all, and third, I was expected to pave them." The expectation of golden streets partially reflects a "rags-to-riches" myth in which Europeans came with only the clothes on their back, but then rapidly climbed the ladder to success. Not so fast, write Abramitzky and Boustan in Chapter 4. While many historical Europeans came from poorer families, they improved at the same rate as the average white US-born worker. The data tell us that there was no quick path to success, on average. While Europeans did not improve on US-born outcomes, they were also not destitute, as they started off on a similar "rung" as the US-born on the occupational ladder. Immigrants climbed the ladder at the same rate as the US-born, but some imped-iments left the first generation "under-placed" in the economic distribution. Without these barriers, the first generation may have climbed even faster than the US born.

While the story of the first generation is not so simple, the story of the second generation in Chapter 5 is straightforward and shines with optimism. Compared to the children of US-born parents of the same socioeconomic background, the children of immigrants ended up with higher economic status. What is shocking about this result is that it holds for nearly all sending countries, as well as across three eras (1880-1910; 1910-1940; and 1980s-2010s). Thus, this pattern appears to be immutable to the dramatic changes of the twentieth century, including changes in source country composition, changes to welfare and educational policy, and changes in the structure of the economy. While this story of upward mobility is certainly optimistic, it is partially due to under-placement in the first generation, which leaves room for upward mobility in the second generation. Under-placement is not the only explanation for intergenerational mobility for the second generation; migrants were savvy enough to move to areas with better prospects for upward mobility.

The comparison of Europeans one hundred years ago to recent cohorts of Asians and Latin Americans is a major theme throughout the book. While upward mobility is similar over time, not everything is constant. Europeans in the past were drawn from poorer families in the source country, whereas migrants today are drawn from wealthier families. While within-country selection has grown more positive over time, the across-country composition of migrants has shifted toward poorer sources. These patterns lead to different rates of economic assimilation over time, where today's first generation starts lower on the ladder but also climbs faster—a difference that can get lost in the book's narrative of similarity over time. Despite these differences over time, the book dispels the popular and pessimistic view that the newer waves of migrants assimilate more slowly than Europeans in the past. In addition to faster climbing of the economic ladder today, Chapter 6 tells us that immigrants today socially assimilate (in terms of intermarriage or adopting foreign-sounding names) at the same rate as in the past. My taste would be to include more figures that concisely convey their findings throughout the book, but Abramitzky and Boustan effectively get their points across.

The book ends with a chapter on how the authors' historical research informs policy today. Abramitzky and Boustan take the long view, at the level of generations. Informed by the upward mobility of the second generation, they argue that qualitative restrictions on entry (e.g., requiring high education) do not matter much in the long run. While economic historians will nod approvingly to this far-sighted view, one wonders whether the average reader will also agree, since in the long run, of course, we're all dead. For those more interested in the short term, the authors point out that most of the negative impacts of immigration are small and dissipate quickly. Thus, the book is a useful coun-terpoint to those who argue for migrant restrictions on economic or cultural grounds.