IS THE SUN BELT finished? Don't believe it. The South and Southwest have taken their drubbings from the economy: oil prices have plummeted, the textile industry would have you believe it's in terrible trouble, farm prices have been falling. But the South and the West, the Census Bureau's latest household survey makes plain, have continued in the 1980s the growth that made them famous as the "Sun Belt" in the 1970s. The South's population rose 7 percent and the West's 6 percent between 1980 and 1984, while population growth in the Northeast was 1 percent and in the Midwest, with its troubled basic industries and ailing Farm Belt, only 0.4 percent. Some 1.9 million Americans have migrated to the South and 600,000 more to the West in the last four years.

To Americans a few decades ago, this would have seemed an unfamiliar pattern: the biggest growth then, outside the lightly populated West, was in the booming immigrant entrepots and industrial metropolises of the East Coast and Great Lakes. But to those for whom only the recent past is familiar, the Sun Belt growth may seem just the continuation of a well-established trend. It is different, however, in two important respects.

First, the growth is concentrated increasingly in metropolitan areas. Fully 80 percent of the South's growth in the 1980s came in such places. In the 1970s there was a lot of growth along interstates within commuting distance of textile mills. Now there's increasing growth in booming medium-sized metropolitan areas -- the Charlottes and Nashvilles that some call mini-Atlantas. This may dismay those who relish a bucolic image of the South. But it probably means better-paying jobs and a more productive economy -- the sorts of things Americans took for granted in the early 1970s but no more.

The second thing to note is that population gain is not uniform across the Sun Belt. It has been most rapid in California, the (sometimes snowy) Rocky Mountain states and the Oil Patch, and minimal in the swath of states in the Mississippi Valley that share some of the economic problems of the Great Lakes and Great Plains states just to the north. Another way to look at it: 40 percent of the nation's population growth was in just three states: Florida, Texas and California. Some 120 years ago all three were economically backward and sparsely populated; now they are richer and more populous than all their neighbors. The Sun Belt is rising again, but it's a different Sun Belt from that of the 1970s and one unimagined by even the most visionary seer of the 1870s.