This paper examines the role of mechanical refrigeration in seasonality and structural change in the U.S. hog–corn
cycle, 1870–1940. This period covers an era in which the widespread adoption of mechanical refrigeration greatly affected the ability to store and transport perishable commodities. These developments in turn altered the seasonal production and price structure for many commodities, including pork. We use a new class of time series models, time-varying smooth transition autoregressions (TV-STARs), to document both the structural change and the nonlinear features observed in seasonal patterns for the U.S. hog–corn price relationship during the late nineteenth and early twentieth centuries.