Crown gall disease caused by Agrobacterium tumefaciens is considered as the main bacterial disease of stone fruit rootstocks in Tunisia against which only prophylactic control measures are available. Therefore, twelve rhizobacterial strains and two reference antagonists Agrobacterium rhizogenes K84 and K1026 were investigated for their efficacy against the causal agent of the disease in vitro, ...

This paper examines how an incumbent’s patent protection acts as an implicit subsidy toward non-infringing substitutes. I analyze whether classes of pharmaceuticals whose first entrant has a longer period of market exclusivity (time between approval and generic entry) see more subsequent entry. Instrumenting for exclusivity using plausibly exogenous delays in the development process, I find tha...

To study how governments can improve the quality of patent screening, we develop an integrative framework incorporating four main policy instruments: patent office examination, preand post-grant fees, and challenges in the courts. We show that examination and pregrant fees are complementary, and that pre-grant fees screen more effectively than post-grant fees. Simulations of the model, calibrat...

We study how competition affects innovation (and welfare) when firms compete both in the product market and in innovation development. This relationship is complex and may lead to scenarios in which a lessening of competition increases R&D and consumer welfare in the long run, contradicting arguments provided by antitrust agencies in recent merger cases. We provide conditions for when a merger ...

We investigate empirically how the Japanese patent system has affected postwar growth in Japanese total factor productivity. The system has been criticized for several reasons, including that it encourages numerous filings of narrow claims that build incrementally on fundamental technologies developed by domestic and foreign inventors. Stated in different terms, the system was designed to promo...

The doctrine of fair use allows limited copying of creative works based on the rationale that copyright holders would consent to such uses if bargaining were possible. This paper develops a formal model of fair use in an effort to derive the efficient legal standard for applying the doctrine. The model interprets copies and originals as differentiated products and defines fair use as a threshol...

This paper reconsiders the explanation of R&D subsidies by Spencer and Brander (1983) and others by allowing firms to license their innovations and to pool their R&D investments. We show that in equilibrium R&D joint ventures are formed and licensing occurs in a way that eliminates the strategic benefits of R&D investment in the export oligopoly game. Nevertheless, national governments are driv...

We reconsider the justifications of R&D subsidies by Spencer and Brander (1983) and others by allowing firms to pool R&D investments and license innovations. In equilibrium R&D joint ventures are formed and licensing occurs in a way that eliminates the strategic benefits of R&D investment in the subsequent oligopoly game. Nevertheless, governments subsidize their domestic firms in order to rais...

We study the incentives that governments have to protect intellectual property in a trading world economy. We consider a world economy with ongoing innovation in two countries that differ in market size and in their capacity for innovation. After describing the determination of national patent policies in a noncooperative regime of patent protection, we ask, “Why is intellectual property better...

Ion-adsorbed rare earth minerals have ions adsorbed on the surfaces of clay such as kaolinite and high contents medium heavy elements. They are important resources supporting development high-tech industries. In this study, CASTEP module in Materials Studio was used to study adsorption ion Y(III) interface (Al-OH)-H2O (Si-O)-H2O with density functional theory. The monitoring calculation chemica...