Plant variety rights and the incentive to innovate

An existing seed industry is considered which faces competition from an innovator who has developed a higher yielding plant variety. Issues examined are: the incentive to innovate; the pricing and dissemination of existing and new varieties through time; and the economic welfare implications. Numerical game theoretic models are developed to illustrate how answers depend on whether the existing industry is competitive or monopolistic, and whether the innovator is accorded plant variety rights.