摘要：Annual mean returns and certainty equivalent returns for 1983-2003 were calculated for specified non-Bt cotton (refuge) percentages for a cotton farm of average size in the Mississippi Delta. Certainty equivalents indicate sprays influence mean profits more than the percentage of refuge in a cotton producer's portfolio. This supports an earlier study where returns calculated from both observed and simulated yields indicated, for any given refuge percentage, mean returns were higher with less risk when insecticides were sprayed compared to no insecticide sprays.
