The changing metropolitan designation process and rural America.

In June 2003, the Office of Management and Budget (OMB) released new county-based designations of Core Based Statistical Areas (CBSAs), replacing Metropolitan Statistical Area designations that were last revised in 1990. In this article, the new designations are briefly described, and counties that have changed classifications are identified. The new designations identify 2 categories of counties or county clusters within CBSAs: Metropolitan Statistical Areas and Micropolitan Statistical Areas. Counties designated as neither are simply referred to as "outside Core Based Statistical Areas." Among counties classified as metropolitan in 1999, 94% are still classified as such, 5% are now micropolitan, and 0.7% are outside CBSAs. The majority of counties that were nonmetropolitan in 1999 remain outside CBSAs (60%), while 28% are now classified as micropolitan and 12% have become metropolitan. The percentage of counties classified as metropolitan has increased from 27.2% to 34.7%, and the population identified as residing in these areas increased from 81% of the total US population to 83%. Some interpretation difficulties may arise in the future, as the naming system lends itself to lumping metropolitan and micropolitan together because of their common designation as CBSAs. The central problem to this classification scheme is that it tracks the urban growth of the nation and its tendency toward agglomeration of markets but pays little attention to the places that are outside CBSAs altogether.