WASHINGTON — Americans are moving at the lowest rate since the government started keeping track, according to Census Bureau data released on Wednesday, as deep changes in the economy and the housing market increasingly freeze Americans in place.

The United States has long been one of the most mobile countries in the developed world. In the 1950s, about one-fifth of the American population moved each year. When factories would close, workers would move to other parts of the country to find jobs in new ones. Young people flocked to cities and rapidly growing suburbs, where jobs were plentiful and rent was cheap.

“In 1957 you could move to a flophouse in New York just to try it out for a while,” said Tyler Cowen, a professor of economics at George Mason University and author of “The Complacent Class: The Self-Defeating Quest for the American Dream.” “That doesn’t exist any more.”

These days, rents in many larger cities have exploded, making it much harder for a young person seeking better opportunities to afford to move. And low-wage jobs, after adjusting for the local cost of living, pay about the same everywhere.