Source: Matthew J. Slaughter, Industrial Relations, Vol. 46 no. 2, April 2007
For decades, the private-sector unionization rate in the United States has been falling. At the same time, the integration of the United States into the world economy has been rising. Many anecdotes suggest the latter has played a role in that decline, with unions feeling pressured to reduce employment and/or compensation demands in the face of rising cross-border activity of employers. To investigate this possibility econometrically, in this paper I assembled a panel of U.S. manufacturing industries that matches union-coverage rates with measures of global engagement such as exports, imports, tariffs, transportation costs, and foreign direct investment. The main finding is a statistically and economically significant correlation between falling union coverage and greater numbers of inward FDI transactions. Possible interpretations of this finding are then discussed. Because U.S. affiliates of foreign multinationals have higher unionization rates than U.S.-based firms do, this correlation does not reflect just a compositional shift toward these affiliates. Instead, it may reflect pressure of international capital mobility on U.S.-based companies, consistent with research on how rising capital mobility raises labor-demand elasticities and alters bargaining power.