Cotton farms and farming in Hebei province, China, over the 2002-2013 period

Surveys implemented in a province where transgenic cotton, made resistant to some pests, has been commercially released since 1997. In addition to capturing what farms growing cotton were, production costs were recorded as well as farmers' opinions about the effectiveness and profitability of the transgenic cotton. Survey questionnaires have evolved slightly over the period, notably with regard to farmers' observation about the pest complex change.