A summary function describing the relationship between output level, conservation reserve program (CRP) acreage, and production costs for major US field crops indicates that extending the CRP from 40 million to 44 million acres in 1990 could raise the bid price for CRP land as much as 7 percent. The estimated effect on commodity prices is modest and depends largely on interactions with other farm programs Previous research has probably overstated the commodity price effects of the CRP because of insufficient treatment of cross-commodity effects