The annual net decline in the number of farms is explained by using the lagged number of farms to account for the longrun trend and several variables representing economic conditions. The trend provides most of the explanatory power during 1960-74, while prices, land values, and interest rates explain deviations from the trend during 1975-88. Projections of farm numbers need to take into account both longrun trends and shortrun variability in economic conditions to produce meaningful estimates.