the size and distribution of benefits from adoption biotech crops have been subjects public debate since commercialization in mid 1990s while many studies investigated these issues their results vary purpose this study is to explain how variability specific factors can lead differences reported measure economic resulting one must consider potential yield enhancements savings pest control costs efficiency technology transfer row producers all context supply demand us global market farm level effects associated with biotechnology shift commodity curve right ie more at a given price leads reduction theoretical framework employed measures change marshallian surplus output model also captures monopoly profits accruing innovators seed input moschini lapan provided for ing welfare changes where new production