Naïve and adaptive schemes have been used as proxies for price expectations in previous studies of supply response. Those studies contain mixed formulas of futures, support, and lagged prices as alternative formulations for price expectations. This study uses a conditional expected price which combines both market and support prices into one price expectations measure. It defines the total effect of available information on supply response. The results indicate the potential usefulness of formulating expected prices as conditional price expectations in supply response analysis, with support prices being the conditional set. Under the provisions of the 1985 Farm Bill, significant reductions in corn and soybean acreages are in prospect for 1987-90.