The Yield of Plant Variety Protection
利用澳大利亚小麦育种行业1976-2011年的数据，研究发现植物品种保护改革导致育种者产出大幅下降，原因包括研究溢出减少、释放标准降低和总投资可能下降。
Abstract The prospects for plant variety protection to deliver improved varieties of self‐pollinating crops is assessed using the experience of the Australian wheat breeding sector as a natural experiment. The analysis is based on detailed new data on the agronomic performance of all wheat varieties released by Australian breeders between 1976 and 2011. The results indicate that plant variety protection, and associated reforms, led to a substantial fall in breeder output. Qualitative evidence indicates that this was caused by a combination of fewer research spillovers, lower release standards, and a possible fall in total investment in breeding.