This article examines the effect of the introduction of plant variety protection on the output of Australian wheat breeders. The Australian experience has global relevance due to the relative strength of plant variety protection introduced in 1994. The analysis uses extensive new data on the performance of all 250 varieties released between 1976 and 2011. A comprehensive framework for measuring breeder output using data from scientific variety trials is developed. The results indicate that plant variety protection led to a 24 percent reduction in annual breeder output. The finding appears to support the conclusion that plant variety protection alone does not generate the socially optimal rate of variety improvement in the case of self-pollinating crops, and therefore, that additional government support is warranted.