Abstract:     With the rapid development of science and technology and cross-domain integration, various industries are generally faced with disruptive changes. The change of innovation environment not only causes anxieties about whether enterprises can maintain their competitive advantages, but also brings them new opportunities. More and more enterprises are increasingly aware that only through internal R&D, it is difficult to maintain sustainable innovation capability, so they seek for various ways to promote technological innovation. Therefore, innovation alliances, boundary-spanning search, technological M&A and other ways of knowledge exchange have been gradually generated. Among these external knowledge acquisition methods, boundary-spanning technological M&A, on the one hand, enables enterprises to break through the original organization and technical boundary, contact and obtain heterogeneous knowledge resources, and on the other hand it helps the enterprise to improve the existing knowledge base, which well responds to the need of enterprises to maintain competitive advantage under current fierce innovation situation. Data showing that recent years, boundary-spanning M&A become more and more active. As a strategic response for enterprises to adapt to the innovation environment of boundary-spanning technology integration, the wave of boundary-spanning M&A has come.
      Knowledge absorption after merger is the key to determine the performance of boundary-spanning technological M&A. Studies have found that there is indeed an interactive relationship between innovative tendency, innovation behavior after technology merger and its effect. In this way, under the background of boundary-spanning, will the differences in innovation tendency also have an impact on the absorption and integration of out-of-bounds technologies after M&A, and what kind of impact? At the same time, the effectiveness of post-merger technology integration decision is limited by the resource characteristics of the enterprise. Will the higher degree of technical asset specificity of the acquirer be adverse to the technology absorption after M&A because of the resistance caused by the transfer of assets purposes? Whether there a way to weaken this adverse effect? To answer above questions, based on the absorptive capacity theory and asset specificity theory, this paper puts the enterprise′s innovation tendency, technology asset specificity and internal & external innovation resource input into a unified framework, and explores the mechanism of the influence of the three factors on innovation performance after boundary-spanning technological M&A, so as to provide references for the relevant M&A decisions for enterprises.
     This paper takes the boundary-spanning technological M&A events of listed companies in China from 2007 to 2015 as samples. Through conditional filtering, 107 samples of boundary-spanning technological M&A events are finally obtained. As for method, this paper uses multiple regression analysis for empirical research.
     The conclusion contains three aspects. First, although enterprises engaged in boundary-spanning technological M&A tend to be more exploratory innovation, but exploitation innovation tendency is more conducive to promote the innovation performance after the merger; Secondly, the degree of specificity of existing technology assets weakens the positive impact of exploitative innovation tendency on innovation performance after merger. Thirdly, internal R&D and innovation cooperation with external institutions will both weaken the negative regulating effect of asset specificity on the exploitation innovation tendency and innovation performance. Compared with external cooperation, internal R&D investment has a better effect on alleviating the specificity of high-tech assets.
    The theoretical contributions of this paper mainly include the following points. First of all, it makes up for the lack of literature in the field of boundary-spanning technological M&A, and answers the question of enterprises with what kind of innovation tendency are more likely to obtain better innovation income through boundary-spanning technological M&A, providing theoretical support for the strategic planning and related decision-making. Secondly, our research extends the existing absorption capacity theory. On the one hand, from the perspective of innovation decision-making, this paper refines the influence of innovation tendency differences on technology absorption process, and embodies driving process and mechanism of enterprise strategy in the process of technology absorption in the theoretical framework of absorption capacity of Lane et al. On the other hand, it deepens the theory of absorptive capacity from the perspective of the characteristics of the knowledge to be absorbed. In the current theoretical framework of absorptive capacity, there are few detailed studies on different characteristics of knowledge. Based on the situation of knowledge integration after boundary-spanning technological M&A, this paper finds out the mechanism of enterprise innovation tendency in absorbing "out-of-bounds" knowledge. Thirdly, it enriches the asset specificity theory from the perspective of technical assets. At present, more researches on asset specificity continue Williamson′s five classifications and focus on the research on the specificity of physical assets in classification. By exploring the influence of technology asset specificity on enterprise innovation behavior, this paper fills in the blank area of asset specificity theory in the field of technology asset, and extends the asset specificity theory to the field of innovation decision-making.
The findings of this paper have certain reference value for the decision of boundary-spanning technological M&A and the evaluation of such technology merger and acquisition events by stakeholders. There are mainly three aspects. First, it provides a systematic solution to the problems of how the innovation tendency of enterprises in the context of boundary-spanning technological merger influences innovation performance and how the specificity of existing technology assets affects the relationship mentioned above. It provides empirical evidence for the relevant decision-making of boundary-spanning technological M&A. Secondly, when conducting this type of technological M&A, enterprises should fully consider the impact of the current innovation tendency on the future knowledge absorption, evaluate whether the enterprises have the strategic environment to extract and integrate the "out-of-bounds" knowledge acquired in the mergers and acquisitions, and adjust the innovation tendency at the right time. Thirdly, the influence of technical asset specificity is inherent, but it should not be an obstacle to the boundary-spanning development of enterprises. In the process of absorbing and integrating the acquired knowledge, enterprises can increase innovation investment and innovation cooperation to offset some of the application inertia and resource locking effect caused by the excessive specificity of existing technical assets, so as to deal with the obstacle of the cross-border development of enterprises caused by the specificity of high-tech assets.

Key words: boundary-spanning technological M&A, dual-element innovation tendency, technical asset specificity, innovation cooperation, innovation input