In my family, moving long distances is the norm.

My mother was born and raised in Honolulu, where her grandmother had moved during the Great Depression from a sleepy upstate New York town on Lake Ontario. (You can read all about it in a novel my mom just published.) As adults, she and my dad left Hawaii for, of all places, New Hampshire, where my brother and I grew up.

(“Why would you leave paradise for the frozen reaches of New Hampshire?” one might ask. Don’t worry, Dan and I asked this many, many times as children.)

My parents met in Hawaii, but my dad was born in France; his dad, born in North Dakota, was a career Army officer, and so my dad and my aunts and uncles grew up everywhere from France to Belgium to San Francisco to Germany to Honolulu.

Our family is a somewhat extreme case, but if you inhabit a certain class position in the United States, this kind of mobility can seem normal. People grow up in one place, but then they go to universities a few hundred or thousand miles away, before moving on to a big city to find work.

But it’s not the norm. A new paper by Harvard’s Ben Sprung-Keyser and Nathaniel Hendren, and the Census Bureau’s Sonya Porter, takes an in-depth look at young adults leaving home. The big takeaway is … they do not.

At age 26, the authors find, 30 percent of Americans live in the census tract they lived in at 16. Fifty-eight percent live less than 10 miles away; 80 percent live less than 100 miles away; 90 percent live less than 500 miles away. Census tracts are tiny, hyper-local designations, with populations between 1,200 and 8,000 each; mine is only 0.2 square miles in area. The small town where I grew up has three tracts within it. Staying within your tract is an extreme level of residential stasis, but 30 percent of young adults do just that. By contrast, huge leaps, like my great-grandmother’s from New York to Honolulu or my parents’ from Honolulu to New Hampshire, are extremely uncommon.

As the demographers and sociologists reading this are likely to point out, the finding that people mostly stay put is not new. Indeed, residential mobility inside the US has been cratering for years, and kept falling even during the pandemic, despite narratives about city residents fleeing.

Where did you come from, where did you go?

While Sprung-Keyser, Hendren, and Porter aren’t the first to find low levels of mobility, the granularity of their data is impressive. They look at “commuting zones,” or collections of cities and towns that make up a regional labor market. For instance, the New York zone includes Long Island and Westchester County, but not farther-away cities like Newark or Poughkeepsie. The authors have data on what share of young adults leave and where they leave for.

You can explore the data yourself here; it turns out that only 1 percent of people from where I grew up move to DC, like I did, which still makes it the third-most-common out-of-state destination after Boston and New York.

The data covers young adults born between 1984 and 1992 — that is, millennials. But there are some indications that the level of residential stasis the authors find is persisting among even younger adults. A recent survey from the personal finance site Credit Karma estimated that 29 percent of Americans between the ages of 18 and 25 live at home with their parents or other relatives; this phenomenon surged during the pandemic, even among people in that age group not enrolled in colleges or universities, before waning as the country reopened.

As you might expect, migration patterns depend a lot on race and income. Black young adults move 60 miles less, on average, than white young adults, and children of the top 1 percent of the income distribution move 325 miles on average, compared to just 160 miles for those whose parents were in the 25th percentile of income. This might seem surprising; there are diminishing returns to income (going from $30,000 to $50,000 in earnings is much more meaningful than going from $100,000 to $120,000), meaning there might be less reason for high-income people to move in search of additional wages. But children of high-income families still move substantially more, and farther, than children of low-income families.

One of the more interesting subgroups the paper examines is Black children of relatively affluent backgrounds. Black young adults from high-income families, the authors find, are driving the “new great migration” into Southern cities like Atlanta, Dallas, and Houston; they are 10 times more likely than Black children of low-income families to move to DC.

The data also lets the paper’s authors measure how people’s movements are influenced by job opportunities. If wages suddenly rise in one region, you’d expect more people to move there — but how many people would you expect to move? This measure is called the elasticity of migration.

The surprising takeaway: Even big changes in average wages don’t spur much movement. The authors consider a shock to a particular commuting zone that increases regional wages by $1,600 a year, which is quite large, especially for people in low-wage industries. Such a shock, they find, would lead more people to move to the area … but in the end, its population would only grow by about 1 percent.

High-income and white or Asian young adults are more sensitive to these regional changes in wages, moving at higher rates in response to them than low-income and/or Black and Latino young adults. And a lot depends on local housing markets. Jurisdictions that allow for increased housing supply in response to new demand, the authors find, see more of an influx when wages there rise than jurisdictions (like, say, San Francisco) that restricted housing supply growth even as their economies boomed.

Do we need to get moving?

What, if any, policy implications does this work have?

One is that policies that boost the labor market of specific places provide the most benefit to those places, not to migrants who might be attracted to them. If a $1,600 wage bump only grows a city’s population by 1 percent, Sprung-Keyser told me in a phone interview, that implies that “99 percent of people benefiting were going to be in that city regardless.”

Now, I don’t know of the existence of “place-based policies” meant to improve job opportunities and wages in a particular city or region (say, the Rust Belt or Appalachia) that actually work, or that we have good evidence of effectiveness for. But this research implies that if policymakers hit on plans that could, for instance, revive the labor market in Detroit, they don’t need to worry about migrants soaking up all the gains. The main winners would be Detroiters.

The bigger question raised by the paper is whether Americans are moving enough. There are big advantages to moving: In previous work with Raj Chetty and Lawrence Katz, Hendren found that public housing recipients who moved to lower-poverty areas as young children earned hundreds of thousands of dollars more over their lifetimes compared to those staying in high-poverty areas. Encouraging moves like that could make people durably better off. Indeed, we have extensive evidence about international migration suggesting that it’s a powerful tool for reducing poverty.

But there are major barriers to mobility, even within the US. Housing policy is the principal one, especially for low-income workers. Economists Daniel Shoag and Peter Ganong note that in 1960, after adjusting for housing costs, wages in New York were 39 percent higher for lawyers, and 70 percent higher for janitors, than they were in the Deep South states like Alabama or Mississippi. By 2010, wages in New York were still 39 percent higher for lawyers — but were 7 percent lower for janitors.

Tellingly, the only reason janitors were worse off in New York was housing costs; they earned more, in actual dollars, than janitors in the South, but it all got eaten up by rent. Allowing for more apartment construction in cities (including, yes, New York City, which is building housing at much too slow a pace) would lower rents and allow more people to move for higher wages.

That said, the phenomenon described in Sprung-Keyser, Hendren, and Porter’s paper can’t be entirely explained by barriers to housing in high-wage cities. Many people simply want to stay where they were raised, even though they could earn more money elsewhere. That won’t change even if rents in big cities were to suddenly become affordable.

We shouldn’t put up barriers to movement for people who want to move. The trickier question for me is how to help people who simply do not want to leave, even if they’re in a struggling area. We don’t have good “place-based policies” to revive such areas. But the stubborn homeboundedness of American citizens means we probably should develop some.