Abstract
In order to enlarge the pool of knowledge available in the public domain, temporary exclusive rights are granted to innovators who are willing to fully disclose the information needed to reproduce their invention. After the 20-year patent protection period elapses, society should be able to make free use of the publicly available knowledge described in the patent document, which is deemed useful. Resistance to pesticides destroys however the usefulness of information listed in patent documents over time. The invention, here pesticides, will have a decreased effectiveness once it enters the public domain. In some cases pesticides lose most of their efficacy shortly after temporary exclusive rights expire. Society’s share of the patent bargain—having new useful knowledge available in the public domain—is lost. Resistance can be slowed down, if pesticide use is limited by optimal compliance. Stimulating proper use is generally not compatible with existing market incentives for patent holders, since these have to be able to maximize profits in order to recoup research and development costs and satisfy obligations to the company’s stakeholders. Another incentive system is needed to ensure longevity of pesticides, which at the same time does not hamper future research