Demographic trends are like the ocean’s undercurrent - from a surface level deceptively still, but actually driving the movement of the entire body of water. Paying close attention to the long-term trends in demographics can therefore be revealing of where a nation may be headed in terms of its politics, culture, and economy. Well-noted by now is the decrease in births occurring in America (and most other developed countries), a decrease so significant that it threatens to actually decrease the total U.S. population for the first time in…ever? Setting aside whether that’s a good or bad thing (most arguments favor bad), I’d like to take a closer look at the myriad components and their trends that contribute to determining America’s changing population.
Change in population is equal to births minus deaths, plus net immigration (immigrants minus emigrants). In America, population growth has historically been driven by immigration (outside of a period of severe immigration restrictions in the early 20th century), and this has particularly been the case as birth rates have fallen over the last several decades. I’ll discuss trends in births and deaths in America in a future post, but in this one, I want to focus on that immigrant component. As a Pew Research article put it, “Immigrants and their descendants are projected to account for 88% of U.S. population growth through 2065, assuming current immigration trends continue”. Where exactly immigrants in the U.S. have originated from and what locations they have resettled in - both of which have drastically changed over the course of American history - is of particular interest to how they will alter U.S. demographics. To analyze these trends I’ll be using data provided by the U.S. Census Bureau’s American Community Survey (ACS) and extracted using IPUMS USA. I’ll be using data from the 2006-2019 samples for consistency of the data and so that I keep the focus on the more recent trends.
Characteristics of Immigrants
Before breaking down where immigrants are moving to in America, let’s take a look at where they’re coming from. For most of its history, the U.S. has been an immigrant magnet, drawing nearly 30 million immigrants from Europe between 1850-1940 alone (Hatton & Ward, 2018). Since the mid-20th century, however, immigrants have increasingly come from outside of Europe - in particular, from Latin/Central America and East Asia. In the chart below, I’ve restricted the sample to include only the top ten birthplaces in 2019 that immigrants were born in - otherwise, there would be way too many lines to tell what was going on. Fortunately, just looking at the top 10 provides us a fairly representative sample, since these ten locations account for 75-80% of total immigration each year since 2006. If I had kept the other birthplaces, most of them would look like flat lines hugging the x-axis relative to the massive inflows from the top 10 birthplaces. You’ll also notice that some of the locations include entire continents - Africa, South America - which unfortunately was the level of aggregation provided in the IPUMS data. Still, it’s incredible to see immigration from single countries such as Mexico, India, or China, eclipsing the total proportion coming from entire continents!
Of course, there are many other ways to group immigrants besides their birthplace or nationality that can provide much more interesting statistics. The above chart doesn’t tell us too much, besides hinting at a recent relative decline in immigrants from Mexico. Other demographics, like age and gender, can provide insight into how immigrants compare to natives - telling us in greater detail how they’re playing into population growth. We can also compare them by their highest educational attainment or their personal incomes. Immigrants in the 21st century tend to be younger than U.S. natives, by an average of about 6 years. Perhaps this is not too surprising - historically immigrants have tended to be young, male, and childless (Hatton & Ward, 2018). Using our more recent sample, however, the gender breakdown of our immigrants is almost identical to natives - 49% male and 51% female. In terms of future population growth, these are promising attributes. Younger correlates with healthier, plus many more working-age years to contribute to the economy. 21st-century immigrants also have a somewhat different distribution of educational attainment and generally lower personal incomes than natives.
This is partly a reflection of how difficult it can be to legally immigrate to the U.S. due to policies that cap the number of visas and other legal forms of entry. The U.S. hands out a very limited number of visas each year, and the policies give priority to higher educated and high-skilled immigrants. This process shapes the overall profile of incoming immigrant cohorts - hence why we see so many immigrants with graduate degrees. Of course, the multitude of premier educational institutions also works as a magnet for drawing in highly educated individuals. Immigration policies alter the distribution of immigrants into certain occupations, though this is also an outcome of many, many other factors. Immigrants really are often the ones to take the undesirable, arduous low-paying jobs - but that’s a discussion for another time. In broader terms, immigrants and natives do have very similar unemployment and labor force participation rates among those age 16 and up - both rates are within 1% of each other in the sample.
While education and income comparisons don’t directly tell us anything about what to expect with population growth and migration decisions, they can be decent predictors. People with higher education and income levels tend to live in dense, urban locations and to have fewer children, often at a later age. We also know that immigrant communities attract new immigrants, for various cultural and economic reasons. So before diving into the data on locations, I can already predict that many immigrants will be residing in cities and likely ones on the coasts (where there are large pre-existing populations of Hispanic and Asian immigrants).
Migrating to Where?
Okay, so I’ve established some basic facts about the background of immigrants to America in the 21st century, but now I’d like to get to the main question of this post. Where are these immigrants settling, and how is that shaping demographic trends in America? The first step is easy: what states do they live in?
As expected, we see that California, New York, and Texas dominate this map. California (the residence of 18% of all immigrants in the sample) and New York (10%) have been immigration magnets for over a century now, and Texas (11%) has certainly been a 21st-century magnet. The next two states with the largest inflow of immigrants are Florida (9%) and New Jersey (4.5%). However, I think a less aggregate view makes for a more interesting comparison.
Breaking the data down by county, we see that immigrants are even more geographically concentrated than the initial state-level view shows. In fact, immigrants are so clustered into a small number of counties that I had to convert the counties map above to a log scale. If I had plotted the raw data, barely any county outside of a few in California, Texas, and New York would be shaded. Outside of California, the Northeast Corridor, and Florida, immigrants are almost entirely clustered into single counties or groups of counties. These counties correspond for the most part to major cities. Over 5% of all immigrants in the sample resided just in Los Angeles County, California; over 4% combined in Queens and Kings counties, New York (portions of New York City); nearly 3% in Harris County, Texas (Houston); over 2% in Cook County, Illinois (Chicago). While these percentages may seem small by themselves, it is astonishing that nearly 15% of millions of immigrants were located in just one of four cities!
In some states, the concentration into small geographic clusters is especially high. 85% of Nevada’s immigrants reside in Clark county - the county of Las Vegas. Cook county, which I mentioned already as Chicago’s location, holds 59% of Illinois’ immigrants, while King County, WA (Seattle) contains 56% of Washington’s immigrant population. While overall state populations are similarly distributed more heavily into cities (hence why they are large cities), the metropolitan bias of immigrants’ residencies has always been a distinguishing feature.
Another way we can break down the data is to compare the share of each county’s total population that is made up of immigrants. Just like with the above “Locations of immigrants” map we are looking at total immigrant populations by county, but now taking into account how that compares to the native population as well. The majority of the counties are gray - these are locations that either have no immigrants or so few immigrants it messes up the heat map scale to include them. For the states that do have significant numbers of immigrants, we see similar results as before: California, the Northeast corridor, and Florida have the highest shares of their population being composed of immigrants.
Since my focus is on trends here, I also compared the percent change in the share of immigrants for each county between 2006 and 2018 - here we see an interesting trend. It seems that while the immigrant population is growing relatively faster than U.S. natives in the Northeast and Midwest, most of the west coast counties have nearly no change in or a decrease in relative share. Part of this may be due to the large already existing immigrant population moderating growth in percentage terms, while counties with small populations can experience large percent increases from small population inflows. Regardless, we continue to see that Florida, Texas, and many individual cities are the primary recipients of new immigrants.
Conclusion
While the changing trends in immigration are a particularly interesting topic to me, it’s certainly not the entire picture. As I mentioned at the start, birth rates have gradually fallen in the US for some time, and these have shaped the socioeconomic landscape as well. In my next post, I’ll replicate the analysis in this post but shift the focus from outside the U.S. to within - by looking at trends in births and deaths. Another important factor is internal migration - how are people moving around across states and within each state? As a native Californian, I’m very familiar with the narrative of Californians moving to Denver, Phoenix, or Texas to escape exorbitant housing prices. The COVID-19 pandemic will surely have long-term effects on people’s decisions to live in cities or suburbs, though the permanency of remote work is yet to be seen.
Any prediction made using only historical data should be taken with a pinch of salt. No one could have predicted how the ongoing pandemic would have unfolded, and such an unexpected event has and will continue to alter the demographic trends. The effect the COVID-19 pandemic will have on immigration, besides the short-term decrease due to border closures, is still in development. Even knowing how immigration will proceed over the next few years is not enough information to characterize long-term demographic trends. Not too long ago, the primary concern was overpopulation. Today, aging societies and stagnating populations appear to be taking center stage.
Notes and Citations
IPUMS Citation: Steven Ruggles, Sarah Flood, Sophia Foster, Ronald Goeken, Jose Pacas, Megan Schouweiler and Matthew Sobek. IPUMS USA: Version 11.0 [dataset]. Minneapolis, MN: IPUMS, 2021. https://doi.org/10.18128/D010.V11.0
Hatton, Timothy and Ward, Zachary, (2018), International Migration in the Atlantic Economy 1850 - 1940, No 02, CEH Discussion Papers, Centre for Economic History, Research School of Economics, Australian National University, https://EconPapers.repec.org/RePEc:auu:hpaper:063.
Charts seen in this post were made in R using the tidyverse, readxl, ggthemes, directlabels, usmap, and RColorBrewer packages. Most of the data collecting, cleaning, and analysis were done in Stata.
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