Interest in the economic role of the large enterprise has led to numerous studies of economic dependency and regional economic health and performance. In this paper, an interindustry accounting framework is conjoined with Dun and Bradstreet corporate ownership data to provide a fresh perspectiveontheeffects of external economicownership. The aggregatelevel measurementmethod is applied to fifteen multicounty regions in the state of Illinois, and reveals considerable variation in the measures generated. High regional dependence measures are directly related to employment stability and inversely related to employment growth.Although interindustry accounts have been used most commonly in economic impacts assessment and forecasting, a broader range of potential applications lies in their use as descriptive and explanatory measurement tools. This paper addresses the external ownership issue at the macrolevel by testing therelationship between measures of input-output dependence and indices of regional employment growth and stability, and demonstrates, in the process, a non-conventional use of interindustry data. The conjoining of interindustry data and the Dun andBradstreet data produces aunique set of measures of regional economic structure.Among the issues associated with regional economic health, development, and welfare, external control seems to evoke strong emotions, Concern ranges from national reliance on foreign oil as an energy source, through the local effects of centralized governmental policy, to the impacts of absentee industry ownership on the local economy. Impacts of foreign direct investment and the relative behavior of foreign and domestic industry have been the research focus of a number of geographers, economists, and regional scientists, who display an ever-increasing interRandall W. Jackson is an assistant professor of geography at Ohio State University. He wishes to acknowledge the helpful comments of William Beyers, Morton 0' Kelly, Donald Jones, Stanley Brunn, and anonymous reviewers on earlier drafs of this paper and from the programming assistance of Cassady Chong, and claims sole responsibility for the final form of the paper and for any remaining errors. He gratefully acknowledges the support of the National Science Foundation Grant SES-8696078,