This paper addresses two issues pertaining to the market differentiation between non-genetically modified and genetically modified food varieties. First, a cost-efficiency explanation of the discrepancy between the observed shares of identity preserved non-genetically modified variety and the total supply of the variety is provided. Second, it is shown that when products can be falsely labeled as non-genetically modified, the share of false labeling depends on the level of identity preservation. Also in this context, it is demonstrated that the share of falsely labeled supply can increase in response to harsher fines.