The role of intellectual property rights in seed technology transfer through trade: evidence from U.S. field crop seed exports
研究了1985-2010年间134个国家的知识产权保护对其从美国进口大田作物种子的影响，发现加入国际植物新品种保护联盟和世界贸易组织知识产权协议能显著促进进口，但效果受进口国收入水平和执法力度影响。
Abstract A panel of 134 countries over the period 1985–2010 is used to evaluate the effect of intellectual property rights (IPRs) on field crop seed imports from the United States. Based on estimating a gravity equation using the Heckman selection and Poisson fixed‐effects panel econometric methods, the results indicate that membership of countries in both the International Union for the Protection of New Varieties of Plants and the Trade‐Related Aspects of Intellectual Property Rights Agreement of the World Trade Organization have a positive and statistically significant effect on their imports of U.S. field crop seeds. These results, however, are also sensitive to both income level of importing countries and better enforcement of IPRs by those countries.