WASHINGTON -- A smaller percentage of Americans are pulling up their roots and moving out of state than at any time since 1950, the Census Bureau said yesterday, suggesting that the great postwar population shifts that reshaped the country's political, social and economic landscape have, for the moment, come to an end.
The Census Bureau figures show an overall decline in Americans' mobility. It said that about 16.7 percent of the population changed residences during a one-year period ending in March 1994, far below the 20 percent that moved in a typical year during the 1950s and 1960s and the second-lowest level of mobility since 1948 when the Census Bureau began tracking such movement. The percentage of people moving from one state to another dropped to 2.6 percent from 3.6 percent.
Demographers, sociologists and economists said the aging of the population, the growth in two-income families, the decline in family size and a continuing sense of financial insecurity all contributed to the trend.
"People are becoming more stable," said Kristin A. Hansen, a demographer with the Census Bureau who produced the study.
While Americans still move with much more frequency than people in Western Europe or Japan, the Census Bureau reported that the proportion of people moving has declined significantly since it hit a postwar high of 20.7 percent in 1964-'65. After a brief spurt in 1984-'85 when 20.2 percent of the population moved mainly because of improving economic conditions, the sedentary trend resumed and has persisted.
And with it, some experts say, the era of the great mid-century migrations -- that of Southern blacks moving North and the rise of the Sun Belt -- may have ended. In its place, some political scientists theorize, is a sense that there is no place left to go to seek a better life.
"That could have something to do with the current political mood," said Walter D. Burnham, a professor of government at the University of Texas.
"We have always been a country based on optimism and new frontiers. This seems like a different world; one that looks more like a frozen river than a fluid stream."
A demographer with the Census Bureau, Larry Long, said, "In spite of what John Steinbeck wrote, the fact is good times generate lots of migration and bad times cause people to stay where they are and hold on to what they've got."
Some sociologists attribute the decline to the increase in the number of two-earner families. With more married women working and with two incomes increasingly needed to cope financially, pulling up stakes becomes more complicated.
"It's harder to get two jobs elsewhere than one," said Peter A. Rogerson, a professor of geography at the State University of New York at Buffalo.
But some experts say the decline in mobility is a natural consequence of the aging of the U.S. population. Moving rates tend to decline with age. Indeed, the report indicates that 35.6 percent of people 20 to 24 years old and 30.7 percent of those 25 to 29 years old changed their residence during the period in question -- the highest rates of any age group.