Before the late 1970's farm-retail price spreads for beef and pork were fairly stable and predictable. Since around 1978-1980, price spreads have (a) increased, (b) become more volatile, and (c) changedseasonal patterns. The reasons for the changes are not well understood. Our inability to account for them has made it difficult for outlook workers to make reliable price predictions. This study investigates possible explanations of the changes in the margins. Finding explanations may pave the way for more reliable price forecasts.