چرا محققان پاداش می گیرند؟ در زمینه فناوری و رقابت بازار  Why are researchers paid bonuses? On technology spillovers and market rivalry

1. Introduction Tax incentives and subsidies for R&D activities conducted by private companies are widely used in many developed countries. Our understanding of the structure of incentives that employed inventors face is however limited, regardless of the fact that labor costs account for a large part of private R&D expenses (about 70% according to Harhoff et al., 2003). Both monetary and nonmonetary incentives (Stern, 2004; Cohen and Sauermann, 2007; Sauermann and Cohen, 2010) appear to be important drivers for inventors’ decisions about where to work (Roach and Sauermann, 2010; Akcigit et al., 2015) and, possibly, aboutthe allocation oftime and effort among multiple job tasks (Manso, 2011; Hellmann and Thiele, 2011). That R&D workers mobility between firms is a potential conduit for knowledge transfers is a recognized fact. Such transfers can produce positive knowledge spillovers (Møen, 2005), but also E-mail address: diego.dandria@gmail.com 1 The views expressed in this study are those of the author and shall not be attributed to the European Commission. Financial support from the German Science Foundation (DFG RTG 1411) is gratefully acknowledged. make competing firms steal market shares from previous employers through partial imitation of product innovations (Bloom et al., 2013). In Kim and Marschke (2005) the authors report that the latter form of rivalry can be so intense at times that “a number of Silicon Valley firms, such as Adobe Systems, Apple, Google, Intel Corporation, Intuit, and Pixar, agreed in 2009 not to approach each other’s employees, even at the risk of violating the U.S. competition law.” The model presented in this study contributes to the literature in two ways. First, it explores the market conditions under which some observed regularities in employed inventors’ pay (an average rise in pay around the time of a patent application) are compatible with rational expectations, inventors mobility, capital investments in R&D, and the existence of knowledge externalities that are transmitted between companies through labor mobility. Second, it derives implications for policymakers with regard to the optimal tax and subsidy scheme to use in order to reach the social optimal capital investment in R&D activities under different types of knowledge transfer regimes. We study the effect of a patent box, a subsidy to R&D capital investments, and a new form of subsidy to bonus pay.