Table 3. GM HT cotton summary of average farm level economic impacts 1996–2012 ($/hectare).

Country	Cost of technology	Average farm income benefit (after deduction of cost of technology)	Type of benefit	References
USA	13–82	22	Cost savings	Carpenter and Gianessi (2002)14 Sankala and Blumenthal (2003 and 2006)15,16 Johnson and Strom (2008)17 Also updated to reflect herbicide price and common product usage
South Africa	15–32	33	Cost savings	Personal communication from Monsanto South Africa and updated since 2008 to reflect changes in herbicide prices and usage
Australia	32–131	30	Cost savings	Doyle et al. (2003)22 Monsanto Australia (personal communications) and updated to reflect changes in herbicide usage and prices
Argentina	17–30	40	Cost savings	Personal communication from Monsanto Argentina, Grupo CEO and updated since 2008 to reflect changes in herbicide prices and usage
Brazil	37–52	91	Cost savings plus yield gains of +2% to +4% (-2% 2012)	Galveo (2010, 2012, and 2013)10-12
Mexico	29–72	177	Cost savings plus yield gains of +3% to +18%	Monsanto Mexico annual monitoring reports8 and personal communications
Colombia	96–187	101	Cost savings plus yield gains of +4%	Monsanto Colombia annual personal communications

(1) The range in values for cost of technology relates to annual changes in the average cost paid by farmers. It varies for reasons such as the price of the technology set by seed companies, exchange rates, average seed rates, the nature and effectiveness of the technology (e.g., second generation “Flex” cotton offered more flexible and cost effective weed control than the earlier first generation of HT technology) and values identified in different studies. (2) For additional details of how impacts have been estimated, see examples in Supplemental Materials, Appendix 1.