The distribution of manufacturing employment across regions of the United States has changed tremendously over time. Shares of manufacturing employment in older, northern regions of the country have declined markedly relative to shares in the Sunbelt regions. But the shifting of manufacturing employment shares goes beyond the wellknown migration of population to the South and West. Manufacturing employment relative to population has also fallen in northern regions, and even the absolute number of manufacturing jobs has declined in these areas as well.

Anecdotal evidence suggests that some of the shift in the distribution of manufacturing employment is due to the movement of particular firms and industries to the Sunbelt in search of lower costs of production and increased proximity to customers. However, other forces driving the shift between regions are also often cited. The fast-growing Sunbelt regions may have benefited from specialization in newer, faster-growing manufacturing industries than those clustered in the North. And the Sunbelt may also have been the preferred location for entrepreneurial manufacturing startups.

This study focuses on two particular questions. First, what is the importance of job shifts within a firm but across regions in explaining regional differences in manufacturing employment growth? Second, to what degree are the varying fortunes of regions due to employment reallocation within industries?