Emerging from the 1980 census is the picture of a nation developing more and more regional competition, as population growth in the Northeast and Midwest reaches a near standstill.

　　This development - and its strong implications for US politics and economy in years ahead - has enthroned the South as America’s most densely populated region for the first time in the history of the nation’s head counting.

　　Altogether, the US population rose in the 1970s by 23.2 million people - numerically the third largest growth ever recorded in a single decade. Even so, that gain adds up to only 11.4 percent, lowest in American annual records except for the Depression years.

　　Americans have been migrating south and west in larger number since World War II, and the pattern still prevails.

　　Three sun belt states - Florida, Texas and California - together had nearly 10 million more people in 1980 than a decade earlier. Among large cities, San Diego moved from 14th to 8th and San Antonio from 15th to 10th - with Cleveland and Washington.DC, dropping out of the top 10.

　　Not all that shift can be attributed to the movement out of the snow belt, census officials say, Nonstop waves of immigrants played a role, too - and so did bigger crops of babies as yesterday’s “baby boom” generation reached its child bearing years.

　　Moreover, demographers see the continuing shift south and west as joined by a related but newer phenomenon: More and more, Americans apparently are looking not just for places with more jobs but with fewer people, too. Some instances-