The Exogenous Effect of Corn Prices on Hog Prices Using Ethanol Production and Corn Seed Research and Development as Instrumental Variables

This paper examines the relationship between corn prices and hog prices in the United States using monthly time-series data in a two-stage least squares regression. Ethanol production and various types of genetically modified corn seed research and development are used as instrumental variables for corn prices to account for endogeneity in the model, by removing changes in corn and hog prices that occur due to the reverse-causal relationship between the two commodities. Ethanol production was determined to be the strongest instruments for corn prices. The results indicate that increases in the price of corn increase the price of hog by a smaller, yet still significant magnitude.