HIS ARTICLE presents the new regional eco-±nomic areas defined by the Bureau of Economic Analysis (BEA) and discusses the procedures used to arrive at this disaggregation of the Nation on an economic basis. 1 The new disaggregation has 172 economic areas, and it replaces the i83-area disaggregation that BEA first defined in 1977 and then revised slightly in 1983 (table i and charts i and 2). The redefinition was undertaken in 1993 largely to incorporate newly available information on commuting patterns. 2 To facilitate regional economic analysis, BEA provides geographically detailed economic data by economic area, as well as by State and by local area. BEA assembles economic area data on earnings by industry, employment by industry, total personal income, population, and per capita personal income. These data may be used to analyze local area economic activity, local interindustry economic relationships, and interarea population movements. In addition, the areas are used as major units for BEA'S local area economic projections. 3 Historical and projected economic area data are used by government agencies for planning public-sector projects and programs, by businesses for determining plant locations and sales territories, and by university and other research groups for doing regional economic studies. Each economic area consists of one or more economic nodes—metropolitan areas or similar areas that serve as centers of economic activity—arid the surrounding counties that are economically related to the nodes. The main factor used in determining the economic relationships among counties is commuting patterns, so each economic area includes, as far as possible, the place of work and the place of residence of its