Abstract:    Both governments and firms should draw attention to how to solve the problem of low efficiency of innovation cooperation of enterprises. Based on the practice and the literature review of the relationship between government R&D subsidies and innovation cooperation of enterprises, this paper takes the panel data of China′s A-share listed companies from 2008 to 2018 as samples, investigated the differential effect of government R&D subsidies on innovation cooperation of enterprises. To be more specific, the moderating effect of Top Management Team(TMT) social capital were discussed and the differences in the moderating role of TMT social capital between heterogeneous firms were investigated. Further, this paper discussed the moderating effect of different types TMT social capital on the relationship between government R&D subsidies and innovation cooperation. 
   The research results showed that government R&D subsidies can promote firm′s innovation cooperation. The TMT social capital positively moderated the relationship between government R&D subsidies and innovation cooperation. The TMT social capital significantly moderated the relationship between government R&D subsidies and innovation cooperation of enterprises only in high-tech firms, non-state-owned enterprises and small- scale firms. TMT overseas social capital and TMT academic social capital significantly moderated the relationship between government R&D subsidies and innovation cooperation of enterprises, while the moderating effect of TMT financial social capital is not significant.
    This paper makes the following contributions. First, this paper adopted a more accurate measurement of innovation cooperation of enterprises and provided more abundant and detailed micro evidence for evaluating the effectiveness of government R&D subsidies in China from the perspective of R&D subsidies′ behavioral additionality. Second, existing literatures mainly discussed the moderating effect of firm′s basic characteristic variables on the R&D subsidies′ behavioral additionality, ignoring the initiative of TMT in firm strategic management decisions. Based on the perspective of firm strategic management, this paper explores the moderating effect of TMT social capital on the relationship between government R&D subsidies and innovation cooperation of enterprises, which provide a new perspective to explain the differential effect of government R&D subsidies on innovation cooperation of enterprises. Third，most of the existing literature regarded the internal factors of the firm, such as firm size and manager′s cognition, as the main factors affecting innovation cooperation of firm. This paper investigated the impact of government R&D subsidies on innovation cooperation, which could expand and supplement the relevant literature on external factors affecting innovation cooperation of enterprises.
    The main policy implications from the perspective of policy makers and firm′s manager are as follows. On the one hand, government can promote technological innovation cooperation between firms using R&D subsidies. While allocating R&D subsidies, it is necessary for government to consider the heterogeneity of TMT in firms. More subsidies should be given to high-tech firms, non-state-owned firms and small firms. On the other hand, TMT needs to use their social capital to communicate with other organizations in order to obtain more market information that is conducive to firms′ decision-making. In particular, TMT of high-tech firms, non-state-owned firms, and small-size firms need to play their role in alleviating information asymmetry, so as to improve the level of mutual trust between firms and improve the efficiency of using government R&D subsidies.

Key words: government R&D subsidy, TMT social capital, innovation collaboration, behavioral additionality