The Impact of Knowledge Spillover from Universities in Sichuan-Chongqing Region on Regional Innovation Capacity

. As an important subject of the regional innovation system, the sci-entiﬁc research activities of universities are not only the power source of talent cultivation and knowledge innovation but also an important force to promote regional innovation development. This paper examines the inﬂuence relationship between knowledge spillover from universities in Sichuan province and Chongqing city and regional innovation capacity from the aspects of teaching and research personnel input, research and development personnel input in research input, monographs, academic papers, technology transfer contracts and transfer income in research output. The results show that the improvement of the innovation capacity in Sichuan province and Chongqing city depends on the increase of teaching and research personnel input and the number of scientiﬁc and technological topics in universities, while other indirect scientiﬁc research results do not contribute signiﬁcantly to the regional innovation capacity; further mechanism analysis reveals that the knowledge spillover from universities mainly promotes the improvement of regional innovation capacity through human capital, physical capital, and scientiﬁc and technological innovation.


Introduction
With the shift of China's economy from the stage of high-speed growth to the stage of highquality development, the labor cost is gradually rising and the bearing capacity of resources and the environment is reaching a bottleneck. The role and influence of innovation in economic and social construction are increasingly prominent, and the regional innovation capacity has become the key factor to promote regional economic growth. From a practical point of view, there are two main ways to enhance regional innovation capacity: first, endogenous innovation through knowledge accumulation; second, exogenous innovation through knowledge spillover. Due to the limited resources within a region, making full use of knowledge spillover to innovate and achieve good innovation results becomes an important issue in academic and practical field.
As the main body of knowledge accumulation, creation, and dissemination, universities are the main component of the regional knowledge innovation system and the important source of knowledge spillover [1,2]. The knowledge spillover from universities to regional innovation includes explicit knowledge spillover and tacit knowledge spillover. Explicit knowledge can be transmitted through normative and systematic language, while tacit knowledge is practical knowledge, which is difficult to imitate or substitute [3][4][5]. On the one hand, universities can realize explicit knowledge spillover by cultivating innovative talents, publishing academic papers, and carrying out academic exchanges, so that knowledge and talents can flow in different spatial scopes [6,7]; On the other hand, universities and enterprises establish the cooperation platform of industry-university-research, and realize the spillover of tacit knowledge through interaction and communication [8].
Knowledge spillover originates from endogenous growth theory. After Arrow proposed the accumulation of knowledge and its economic connotation [9], Romer further found that the non-competitive and partially exclusive characteristics of technological knowledge are the fundamental reasons for knowledge spillover, and introduced knowledge as an independent factor into the production function to establish the endogenous growth model of knowledge spillover [10]. Initially, the research on knowledge spillover in universities mainly focused on the enterprise level, with Audretsch and Feldman pointing out that the relationship between knowledge spillover and innovation output is more significant at the regional level [11], the focus of research on knowledge spillover gradually shifts from the micro level such as enterprises to the macro level such as regions, and the relationship between knowledge spillover in universities and regional innovation becomes an important issue of scholars' attention. Some studies point out that the uneven distribution of companies around universities is the best evidence that universities have a positive effect on regional innovation [12,13]. At the same time, some studies have also shown that collaborative networks between universities and companies can promote knowledge spillovers, which in turn increase innovation activities in the region [14,15]. While most studies have found a significant knowledge spillover effect of universities on regional innovation, others have shown that this is not the case. Escribano A et al. show that external knowledge spillover does not directly affect regional innovation capacity, but only internalization and absorption of knowledge can enhance regional innovation capacity [16]. After analyzing the strategic framework of the entrepreneurial university, Audretsch further found that as the university's role gradually changes from investing in knowledge and technology transfer to engaging with multiple stakeholders outside the university, the university's internal institutions and culture may reduce the impact of universities on regional innovation [17]. This shows that in the empirical study, there is no consensus on whether knowledge spillover from universities can influence regional innovation capacity.
There have been abundant studies on the relationship between knowledge spillover and regional innovation capacity, but they are mainly based on the spatial perspective to explore the distribution effect of knowledge spillover, while the studies on the relationship between university knowledge spillover and regional innovation capacity are not in-depth sufficient. Therefore, this study analyzes the influence of university knowledge spillover on regional innovation capacity from the dual perspective of university research inputs and outputs, and further investigates the influence mechanism of university knowledge spillover on regional innovation capacity.

Variables Description
This paper takes Sichuan Province and Chongqing City as the study areas. As an important population, town, and industry cluster in China, Sichuan Province and Chongqing City have an important strategic position in the overall modernization of China. Under the background of the "Western Higher Education Revitalization Plan", many universities in Sichuan Province and Chongqing City initiated and established the "Chengdu-Chongqing Region Twin Cities Economic Circle University Alliance" to give full play to the advantages of universities in talent gathering, talent development, and talent utilization so as to provide intellectual support for regional economic development.
The core explanatory variable is regional innovation capacity. In this paper, the number of patent applications in Sichuan Province and Chongqing Municipality from 2009 to 2019 is selected as a measure of regional innovation capacity. The selection of regional innovation capacity indicators is mainly based on the following considerations: Firstly, the patent volume has become an important indicator of innovation capability in empirical studies, and its reliability and robustness have been fully verified. Secondly, there is a time lag from the application to the grant of a patent, thus the number of patent applications can accurately reflect the regional innovation capacity compared to the number of patents granted.
Knowledge spillover from universities is the core explanatory variable in this paper. In terms of knowledge spillover of universities, some scholars believe that knowledge spillover of universities involves both financial expenditure and personnel input [18], and some scholars analyze the knowledge spillover effect of universities from the perspective of innovation output [19,20]. Based on the existing research, this paper takes into account both explicit and tacit knowledge spillover, to explore the influence of university knowledge spillover on regional innovation capability from the perspective of both university research inputs and outputs. To be specific, the input variables of university research include the number of university teaching and research staff and the number of research and development staff, while the output variables of university research include the number of university science and technology topics, the number of monographs and the number of academic papers.
Meanwhile, this paper further explores the mechanism of knowledge spillover from universities on regional innovation capacity by using human capital, physical capital, and technological innovation as mediating variables. Among the mediating variables, human capital is the proportion of graduates from general universities in Sichuan province and Chongqing city in the employed population, physical capital is measured by the annual total social fixed asset investment in the tertiary industry in Sichuan province and Chongqing city, and technological innovation is measured by the number of effective invention patents in high-tech industries in Sichuan province and Chongqing city. In addition, besides knowledge spillover from universities, other factors affect the development of regional innovation capacity. In this paper, the development level of regional cultural undertakings, market openness, and government investment in science and technology are selected as control variables, among which the development level of regional cultural undertakings is measured by the number of public libraries in Sichuan province and Chongqing city, market openness is measured by the total amount of imports and exports in Sichuan province and Chongqing city, and government investment in science and technology is measured by the financial expenditure of Sichuan province and Chongqing city government on science and technology.

Model Construction
The Griliches-Jaffe knowledge production function is a classical model for studying knowledge spillover effects, which uses an input-output approach to study innovation activities. The specific equation is as follows: Where Y is the knowledge output, K denotes the material input of R&D, H denotes the human input of R&D, β1 and β2 denote the elasticity coefficients of knowledge brought by the material input of R&D and the human input of R&D, respectively, and ε is the error term.
To study the influence of universities on regional innovation, the Griliches-Jaffe knowledge production function is further extended and the two sides are taken logarithmically to obtain Model (1), which is shown below.
In model (1), Ininn represents the regional innovation capacity, and the subscript i denotes the year. R&D is the university research input and output, and the coefficient α measures the knowledge spillover effect of university research input and output on the regional innovation capacity. X is the set of control variables, c is the constant term, and µ is the random error term of the model.

Results and Discussion
In the empirical research part, this paper examines the relationship between research inputs and outputs of universities in Sichuan province and Chongqing city on regional innovation capacity by the testing model (1) with the least squares regression method (OLS), and the results are shown in table 2.
Column (1) includes only the university research and development input variables. The regression coefficient shows that the elasticity coefficient of research and development personnel input on the number of regional patent applications is negative (-2.167), which means that the research and development personnel input of universities has an inverse effect on the improvement of regional innovation capacity. The possible reason is that although universities in Sichuan province and Chongqing city have improved the investment in research and development personnel, the quality of scientific research innovation is not high, and there are phenomena such as insufficient per capita research investment and inefficient research performance, which in turn affect or even inhibit the improvement of regional innovation capacity. And the elasticity coefficient of university teaching and research staff investment on the number of regional patent applications is positive (5.018), namely, every 1 unit increase in university research and development staff results in a 5.018 unit rise in the number of regional patent applications. It shows that compared with research and development personnel, teaching and research personnel have higher innovation performance in research output, and their positive effect on improving regional innovation capacity is more obvious.
Column (2) examines the effect of university research output variables on the number of regional patent applications. From the regression results, although the elasticity coefficient of university science and technology topics on regional innovation capacity is positive (0.407), it is not statistically significant. The elasticity coefficient of the academic paper output of universities on regional innovation capacity is 1.170 and is statistically significant at the 1% level. It indicates that every 1 unit increase in the academic paper output of universities leads to 1.17 units increase in the number of regional patent applications. While the elasticity coefficient of the number of university monographs on regional innovation capacity is negative (-0.752), the possible reason is that the current publication of university monographs is mainly based on the need for assessment tasks, which not only fails to achieve knowledge innovation but also consumes the time and energy of university researchers.
Columns (3) and (4) add relevant control variables on the basis of university research input and output variables. From the regression results, the effect of university research and development personnel on regional innovation capacity is further weakened, and the effect of university teaching and research personnel on regional innovation capacity also shows an inverse effect. At the same time, the coefficient of the influence of the university output variables on regional innovation capacity becomes larger. It indicates that the influence of university input and output on regional innovation ability will be influenced by the development level of regional cultural undertakings, market openness, and government science and technology input.

Mechanism Analysis
With the extension of university function from talent cultivation and scientific research to social service, the trend of integration of higher education, science and technology, and economy is increasingly strong. Especially in the knowledge economy society, universities will be pushed to the center of social development and become an important driving force for social development. As an important part of regional innovation, universities mainly enhance regional human capital, physical capital as well as technological capital by the path of knowledge spillover and technology diffusion, which in turn affects regional innovation capacity [21].
In terms of human capital, the scientific and technological innovation talents gathered by universities are an important force to advance regional innovation. Through patent licensing and technology transfer, university researchers promote the R&D activities of other innovation subjects and realize the improvement of regional innovation capacity. In addition, the high-quality talents cultivated by universities are the backup force for knowledge production in universities and an essential guarantee for the sustainable development of regional innovation [22].
As for the material capital, with the formation of a university-industry cooperation relationship between universities and regional enterprises, the university and enterprises support each other, complement each other's advantages and use each other's resources, the ratio and structure of production factors of enterprises are optimized, which plays an influential role in improving the strength of enterprises and accelerating the accumulation of material capital of enterprises [23,24]. In addition, the knowledge spillover effect of university R&D can also promote industrial agglomeration and the development of high-tech industry, which also contributes to the realization of physical capital accumulation and ultimately the improvement of regional innovation capacity.
In respect of technological innovation, as the basic research engaged in by universities has the property of public goods, this positive externality will affect the surrounding enterprises in the form of knowledge spillover, which not only can improve the enterprises' ability to adapt to new technologies and products, accelerating the speed of technological innovation and imitation, but also help promote industrial upgrading through technological innovation, thus optimizing the ratio of production factors in the region, changing the way of product production, giving rise to new products and industries, and ultimately enhance regional innovation capacity [25].
In order to further investigate the influence mechanism of university knowledge spillover on regional innovation capacity, this paper selects human capital, physical capital, and technological innovation as mediating variables to empirically test the effects of university R&D inputs and outputs on regional human capital, physical capital, and technological innovation. The resulting mediating effect model is constructed as follows: (2) Figure 1. Theoretical mechanism of knowledge spillover from universities to promote regional innovation capacity In model (2), M represents the mediating variables, including human capital, physical capital, and technological innovation, and the subscript i indicates the year. R&D represents university research inputs and outputs, and the coefficient β measures the impact of university research inputs and outputs on regional human capital, physical capital, and technological innovation. X is the set of control variables, c is a constant term, and µ is the random error term of the model. Table 3 shows the regression results of the effect of university knowledge spillover on regional human capital, the first column is the effect of university research input on regional human capital, and the second column is the effect of university research output on regional human capital. From the regression results, it can be seen that the results of the impact of university research and development personnel on regional human capital are negative but not significant in terms of university research inputs. In contrast, the result of the effect of university teaching and research staff on regional human capital is positive and significant at the 5% statistical level. That is, for every 1 unit increase in the input of university teaching and research staff, the level of regional human capital increases by 0.00377 units. This indicates that compared to research and development personnel who are mainly engaged in scientific research and experimental development activities, teaching and research personnel need to fulfill the teaching task of talent cultivation and have a greater impact on regional human capital. In terms of university research output, the results of the effects of university science and technology topics and academic papers on regional human capital were positive and statistically significant at the 5% level. According to the regression results, the level of regional human capital increases by 0.00284 units for each unit increase in scientific and technological topics in universities; and the level of regional human capital increases by 0.00136 units for each unit increase in academic papers in universities. The effect of the number of monographs in universities on the regional human capital level is not significant, which indicates that the impact of scientific and technological topics and academic papers on regional human capital is greater compared to the publication of monographs. Table 4 shows the regression results of the impact of university knowledge spillover on regional physical capital, the first column shows the impact of university research input on regional physical capital, and the second column shows the impact of university research output on regional physical capital. The regression results indicates that there is no significant relationship between university research inputs on regional physical capital. In the second column, the coefficient of the effect of university scientific research topics on regional physical capital is 1.866 and is significant at the 5% level, while the coefficient of the effect of The X represents the control variables. *** p<0.01, ** p<0.05, * p<0.1 university academic monographs on regional physical capital is significantly negative and university academic papers have no significant effect on regional physical capital. The regression results show that the influence of university research output on regional physical capital is mainly realized through science and technology topics, and each 1 unit increase in university science and technology topics increases regional physical capital by 1.866 units. Science and technology topics in universities are scientific and technological activities organized and implemented by universities based on the development needs of national science and technology innovation, with the financial support of governments at all levels or regulated and guided by macro policies. Science and technology topics of universities provide strong support for governments at all levels to adjust regional industrial structure and optimize industrial layout, thus influencing the level of regional physical capital. Therefore, compared with other university research outputs, the impact of university science and technology topics on regional physical capital is more obvious. Table 5 shows the regression results of the influence of university knowledge spillover on regional science and technology innovation, the first column shows the influence of university research input on regional science and technology innovation, and the second column shows the influence of university research output on regional science and technology innovation. The regression results show that relative to the university research output, the university research input has a significant effect on regional science and technology innovation. In terms of regression coefficients, the coefficient of influence of university teaching and research personnel on regional science and technology innovation is 4.265 and is significant at the 5% level. It shows that every increase of 1 unit in university science and technology topics will make the number of effective invention patents in the regional high-tech industry increase by 4.265 units. And the impact coefficient of university research and development personnel on regional science and technology innovation is negative (-2.813), that is, increasing the input of university research and development personnel will instead reduce the level of regional science and technology innovation, which seems to be contrary to the empirical fact. However, combined with the current status of scientific research in Chinese universities, it is not difficult to find that the reason may be related to the low conversion rate of R&D results. Due to various reasons such as concept, policy, and system, scientific research in Chinese universities has long shown a situation of "emphasizing results but not practice, emphasizing scientific research but not transformation", and the transformation rate of scientific and technological achievements in Chinese universities is only 8.1% in 2019. In addition, the evaluation system of scientific research in universities pays too much attention to the academic value of scientific research results and neglects the socio-economic value, so that researchers only focus on the rationality of the principle and the technical advancement when selecting a topic, but ignore the feasibility of production and the economy of application, which eventually causes more basic theoretical research and less scientific research that can be directly transformed and applied to production [26].

Conclusion and Recommendations
This paper takes R&D knowledge spillover from universities in Sichuan province and Chongqing city as the research object, and empirically analyzes the effect of R&D knowledge spillover from universities on regional innovation capacity by selecting variables such as teaching and research personnel input, research, and development personnel input, science and technology topics, monographs and academic papers in terms of scientific research input and output, and explores the influence mechanism of the knowledge spillover effect from universities on regional innovation ability. The empirical results show that, in terms of university research input, teaching and research personnel play a more obvious role in improving regional innovation capacity than research and development personnel; in respect of university research output, the effect of university science and technology topics on regional innovation capacity is more significant. Further mechanism analysis reveals that knowledge spillover from universities mainly promotes regional innovation capacity through human capital, physical capital, and technological innovation.
In conclusion, in order to effectively enhance the level of R&D knowledge spillover from universities and promote regional innovation development, this paper argues that the following aspects can be taken into account.
(1) Optimize the structure of scientific research investment in universities, and improve the mechanism of diversified social investment. Although the investment in scientific research of universities in Sichuan-Chongqing region has increased significantly in recent years, there is still a gap compared with the eastern region, and increasing the investment in scientific research is an inevitable choice for the implementation of an innovation-driven strategy. Specifically, the first is to increase government funding and appropriately increase the proportion of scientific research funds in the local financial expenditure of universities in Sichuan province and Chongqing city. Second, pay attention to the main role of enterprises and encourage them to strengthen their cooperation with universities through the formation of innovation consortia and other means [27,28]. Third, improve the diversified investment mechanism of the whole society, and expand the channels of social donation, risk investment, financial technology products, and other sources of funds for scientific research in universities [29,30].
(2) Improve the incentive system of scientific research innovation and stimulate the innovation ability of university researchers. The development of talents is an important factor in the development of scientific and technological innovation, and it is crucial to improve the cultivation and incentive mechanism of university researchers for the growth and development of scientific and technological talents. On the one hand, it is necessary to build a favorable institutional environment conducive to the growth and development of talents, and improve the basic treatment and welfare of researchers, so that researchers have good life security and can devote sufficient time to do scientific research work [31]. On the other hand, we should promote Sichuan province and Chongqing city universities to effectively improve the talent classification and evaluation system, improve the income distribution mechanism based on performance assessment, optimize the allocation of scientific research resources, strengthen the original orientation of basic research and the support and leading role of applied science, and strongly stimulate the innovation vitality of scientific researchers [32].
(3) Improve the transformation mechanism of scientific research achievements and build an integrated platform for regional industry-university-research. Universities in Sichuan province and Chongqing city have high output in scientific research achievements, but due to the imperfect conversion mechanism of scientific research achievements, some achievements are in the state of precipitation or idle, and cannot be transformed into real productivity. Firstly, the local government should be based on the current situation of regional development, constantly strengthen the mechanism of university-industry cooperation, improve the trust degree of university-industry cooperation, constantly build the policy guarantee system to promote the transformation of scientific and technological achievements of universities, and vigorously promote the smooth operation of the transformation system [33]. Secondly, as an important source of scientific research results, Sichuan province and Chongqing city universities should establish stable and lasting university-enterprise cooperation relationships and long-term mechanisms with enterprises according to the requirements of the market mechanism, and participate in the transformation of scientific research results in the whole process, so as to realize the successful transformation of scientific research results [34]. Finally, the industry association, as a scientific research intermediary, should strengthen the core competitiveness of intermediary services, coordinating various activities within the industry, enhancing the ability to coordinate and promote the transformation of scientific research achievements of universities.