Exploring 200 years of U.S. commodity market integration: A structural time series model approach

This paper uses a structural time series model to explore U.S. commodity market convergence, efficiency, and intertemporal smoothing from 1750–1949. I find near-continuous convergence that is largely concentrated in the frontier, broad antebellum efficiency gains, and intertemporal smoothing from the 1880s onward among the most perishable goods. The results reveal new periods of integration across all three metrics and underscore the rapid rate of integration on the frontier.