The main explanations of the effect of sugar prices on high‐fructose corn syrup (HFCS) consumption in the United States are briefly reviewed. A formal model is presented and estimated in a reduced form for the period 1971‐88. The hypothesis that sugar prices affect HFCS consumption growth is confirmed. The estimated model is used to analyse both the effect on HFCS consumption of the two peaks in sugar prices which occurred in 1976‐75 and in 1980, and the effect of the protection applied to the US sugar market. The model is also used to estimate the extent to which the rapid expansion of US HFCS consumption can be attributed solely to the 1974 peak in the international sugar