Tarnishing silver bullets: Bt technology adoption, bounded rationality and the outbreak of secondary pest infestations in China

The adoption of Bt cotton has had a huge impact on global cotton production. Many studies have focused on the potentially positive impact of Bt and the savings on pesticides targeting primary pests. However, in China, growing secondary pest populations have slowly eroded the benefits of Bt technology.

This paper illustrates the effects of introducing Bt technology among farmers with an imperfect knowledge of secondary pest problems using a simple dynamic model. The stochastic dominance tests based on primary household data from 1999-2001 and 2004 in China provide strong evidence that secondary pests, if unanticipated, could completely erode all benefits from Bt cotton cultivation.

The authors note that:

• in order to help farmers make a more informed decision regarding Bt adoption, some effort must be made to educate farmers of the potential for secondary pest infestations
• planting refuge concurrent with Bt adoption provides for the sustainable development of Bt technology as the pesticide required to maintain the refuge will reduce the threat of the secondary pest before they proliferate to a damage concentration
• the profits lost on the refuge could be compensated by substantial savings on pesticides that otherwise would be used to combat outbreaks of the secondary pest in the future

The authors conclude by asserting that Bt cotton and indeed, GM crops more widely, show great promise in improving the lives of farmers in developing nations, if they can be taught to implement them in a sustainable fashion. However, since the adoption of such crops requires technology-specific knowledge, without the necessary training GM crops may prove no better than conventional methods.