This paper investigates the response of beef cattle producers to changes in the price of cattle. Previous research has suggested that there may be a negative short-run supply response to a permanent increase in the price of cattle. We build a dynamic, rational expectations model that predicts that the supply response is generally positive, even for permanent shocks in the short run, and nests the negative supply response as a special case for appropriately restricted demand shocks. Using annual US time series data (1930-1997) and a simultaneous-equations econometric approach, we find a positive short-run supply response in the cow market and mixed evidence in the heifer market.