A New Paradigm of Open Innovation under Chinese Mod-ernization: Co-innovation Theory Review

. Co-innovation is a new paradigm and a new hot spot in the ﬁeld of technological innovation. This study uses bibliometric analysis and CiteS-pace to analyze the co-innovation related literature published at domestic and abroad during 2010-2022 to explore the current status and development trend of co-innovation research. The research results show that co-innovation research at domestic and abroad is developing rapidly and increasingly becoming a research hotspot in the ﬁeld of technological innovation. Compared with foreign scholars who have begun to quantify and case study the technological paths of co-innovation, domestic research still mainly relies on qualitative methods to theoretically explore the institutional mechanism of co-innovation, which can hardly meet the development needs of co-innovation policy and practice. Therefore, this study proposes future research directions for co-innovation in four major aspects: mechanism of action, network model, empowerment mechanism and governance mechanism. As the ﬁrst systematic study of co-innovation literature in China and abroad, this study has important theoretical signiﬁcance and practical value.


Introduction
Since the reform and opening up, China's economic level has been raised to a new height, and the technological innovation of enterprises has also made rapid development. However, compared with the world's advanced enterprises, there is still a large gap between the technological innovation of Chinese enterprises, which is mainly manifested in the large number but low quality of patents, the lack of integration ability of internal and external resources, and the existence of industrial differences [1]. At the same time, the technological innovation of Chinese enterprises also has the problem of unbalanced regional development, and the technological innovation efficiency of enterprises in central and western regions lags behind that of eastern regions, among which the nature of enterprises, human capital and industrial structure are the primary factors affecting the efficiency gap [2]. More importantly, at this stage, both large enterprises and SMEs in China are facing their own technological innovation bottlenecks, which increasingly cause China's "neck sticking" dilemma in key core technology areas. First of all, from the global economic development history, SMEs have played a pivotal role in promoting national technological innovation, but at present, China's SMEs have high production costs, competitive market pressure and shortage of innovation resources have inhibited the technological innovation drive of enterprises in China [3]. At the same time, although China's large enterprises have a good capital for technological innovation, but the innovation vitality is obviously insufficient [4]. In order to strengthen the main position of enterprise science and technology innovation, play a leading role in supporting science and technology backbone enterprises, create a good environment conducive to the growth of science and technology-based small and medium-sized enterprises, and improve the "neck sticking" dilemma in the field of China's key core technologies, the Fourth Plenary Session of the 19th CPC Central Committee proposed "to establish an enterprise-oriented, market-oriented, industry-academia-research depth". The Fourth Plenary Session of the 19th CPC Central Committee proposed "to establish a technology innovation system with enterprises as the main body, market-oriented, and deep integration of industry, academia and research, and to support co-innovation for large, medium and small enterprises and all kinds of subjects", which marked that the new technology innovation paradigm of "co-innovation" was officially put into policy practice. As a result, how to correctly understand and promote co-innovation has become a theoretical proposition that needs to be broken through in the field of innovation management.
As a new paradigm in the field of technology innovation, co-innovation can be traced back to collaborative innovation and further to the open innovation proposed by Chesbrough in his 2003 book "Open innovation: the new imperative for creating and profiting from technology". Compared to traditional closed innovation, the major difference of open innovation is that it blurs the boundaries of an organization's innovation activities, allowing it to obtain valuable resources from both external and internal sources to transform and commercialize its R&D results [5]. Collaborative innovation is a more advanced organizational model of the open innovation paradigm, which manifests itself in the sharing and integration of knowledge and resources among enterprises, governments, universities, research institutions and other types of diverse subjects to achieve major scientific and technological innovation [6]. With the progress of modern science and technology and the evolution of global competition pattern, the organizational boundary of enterprise technology innovation activities needs to be changed from fuzzy to completely broken, the innovation elements of various innovation subjects need to be completely reorganized, the innovation "silos" need to be completely eliminated, and the open innovation of enterprises needs to be completely upgraded, so that new technological breakthroughs in key core fields can be truly realized [7]. In this context, co-innovation is seen as a new paradigm to solve the technological innovation problems of Chinese enterprises in the new development pattern of "Dual Circulation".
However, like most practices that are ahead of theory, the existing domestic and international studies have not yet been able to fully reveal the theoretical connotations and mechanisms of co-innovation, resulting in the policy practice of co-innovation is still in the exploratory stage. Therefore, based on bibliometric analysis, this study analyzes the frontier research on co-innovation at home and abroad that emerged between 2010 and 2022, and aims to systematically and comprehensively explain the theoretical connotation of co-innovation and outline its research status, so as to find out a theoretical research path of co-innovation that meets the needs of practical development.

Concept Definition: Co-innovation
Based on the conference documents adopted by the Fifth Plenary Session of the 19th CPC Central Committee held in China and the definition of co-innovation by Chen Jin et al, this study defines co-innovation as a new paradigm of open innovation between large, medium and small enterprises, state-owned and private enterprises, and industry, academia and research institutes, which achieves deep integration of industrial and innovation chains by integrating and complementing resources, collaborating and sharing knowledge, creating value and sharing risks with multiple subjects in external innovation networks, with the actual needs of society and value creation as the guide [8,9]. Unlike traditional open innovation and collaborative innovation, co-innovation places more emphasis on the unified leadership and strategic deployment of technological innovation by the Chinese government, the platform resource advantages and innovation leadership of China's backbone state-owned enterprises and large private enterprises, and the deep integration among enterprises of different scales and ownership, with the goal of building a strategic innovation system with complementary advantages, resource sharing, mutual benefit and value creation among various innovation entities. The goal is to build a strategic innovation ecosystem in which all kinds of innovation agents have complementary advantages, share resources, benefit from each other and create value together. Therefore, in order to differentiate from the traditional open innovation and collaborative innovation literature, this study further distinguishes the themes of the retrieved literature, and limits the themes to cooperative technology innovation research in which the organizational boundaries between large, small, medium and large enterprises, as well as between state-owned and private enterprises, are completely broken, and the deep integration between industrial and innovation chains is achieved.

Literature Collection and Research Boundaries
(1) Search boundary. Web of Science and CNKI databases were selected as the search sources, and the validity of the literature was confirmed according to the following three rules based on the standardized sampling method: first, literature relevance screening based on research topics and abstracts, second, de-duplication of all search results, and third, reading the content of the remaining literature and eliminating irrelevant literature, and finally 217 valid search results were obtained (see table 1 for details). The total number of valid search results was 217 (see table 1).
(2) Search keywords. First of all, for domestic literature, the search keyword was determined as "integration innovation", because this topic is still in the early stage of research, the number of publications is relatively small, only 48 articles were retrieved, and the number of valid documents that meet the requirements of the concept definition of this study through content screening is only 14. In order to better analyze the development of co-innovation research, we added the search terms "innovation chain", "industrial chain" and "innovation of large and medium-sized enterprises" according to the characteristics of co-innovation integration mode and the characteristics of participating subjects. The search terms "innovation chain", "industrial chain" and "innovation of large and medium-sized enterprises" were added to the search list, and a total of 148 papers were obtained through content screening. Then, for the foreign literature, considering that "co-innovation" is the first policy practice in China, this study refers to the translation by Chen Jin, a representative scholar of co-innovation theory in China, and also translates it as "co-innovation". Through the search, we found that the definition of "co-innovation" in foreign literature covers the cooperative innovation network co-innovation 2. Select "SCI source journals", "PKU core", "CSSCI" and "CSCD" for "Source category". 48 14 large, medium and small enterprises & innovation 11 5 Web of Science Excluding duplicates, the total remaining 217 between the public sector and social capital [10][11][12], the intermediary platform in the cooperative innovation network [13,14], and the value co-creation activities of different innovation agents, such as suppliers and customers, in the innovation process [15], which is consistent with the scope of "co-innovation" proposed in this study. The scope of fusion innovation is consistent with that proposed in this study. On this basis, through content screening, we find that some of the studies on open innovation and innovation ecological network reflect the characteristics of co-innovation, so we add "innovation platform", "innovation ecosystem" and "open innovation platforms". Therefore, we added "innovation platform", "innovation ecosystem" and "open innovation platforms" as search terms, and obtained a total of 78 valid documents.
(3) Time frame. In order to clarify the temporal lineage of co-innovation research as comprehensively as possible, this study determined the search time frame as 2000-2022. The search results are shown in table 1. The earliest foreign study that embodies the idea of coinnovation can be traced back to the study of Spaeth et al. on open innovation promotion model in 2010 [16]. The earliest domestic study embodying the idea of co-innovation is Liu Kang and Zeng Fanhua's study on enterprise technology innovation and industrial technology chain integration in 2011 [17].

General Research Trends
By comparing the trends of domestic and foreign publications, as shown in figure 1, the research related to co-innovation has shown a good growth trend. The first phase is the initial exploration phase from 2010 to 2018, with an earlier start abroad and a later start at home, but the average annual publication volume at home and abroad is only about 5 articles, and the concept of "co-innovation" has not yet been clearly proposed; the second phase is the flourishing phase from 2019 to 2022 As a strategic upgrade of the traditional open innovation paradigm, the concept of "co-innovation" was formally proposed at the Fifth Plenary Session of the 19th CPC Central Committee of China, which triggered an explosion of related research in China. As a strategic upgrade to the traditional open innovation paradigm, the concept of "co-innovation" was formally introduced at the Fifth Plenary Session of the 19th CPC Central Committee of China, triggering a "blowout" of related research in China and becoming an increasing research hotspot in the field of global technological innovation.

The Cluster Analysis of Keywords
This study used keyword clustering in CiteSpace to directly analyze the topics of coinnovation research, and the Log Likelihood Ratio (LLR) was selected for clustering the keywords of literature with the default parameters unchanged [18]. The clustering results of domestic and foreign literature are shown in figure 2 and figure 3. The Modularity Q values were 0.8607 and 0.7873, which were much higher than the general criteria of significant structure of clusters (Q ≥ 0.3), indicating that the clusters had a clear structure and high network stability. Meanwhile, the Mean Silhouette values (S values) were 0.9724 and 0.8628, respectively, which were higher than the general criterion (S ≥ 0.7) of excellent clustering effect [19], indicating that the clustering themes were clear and of high reliability. As shown in figure 2, the research on domestic co-innovation mainly focuses on the core issues at the macro level, such as "high-tech industry", "industrial chain", "whole chain integration", "innovation consortium", "innovation ecosystem", "symbiosis theory", "new Pasteur quadrant", "digital application technology". In contrast, foreign co-innovation research not only pays attention to the core issues such as "ecosystems", "innovation ecosystem", "co-innovation", but also pays attention to the specific issues of micro innovation subjects, such as innovation networks based on innovation intermediary platform between core large enterprises and SMEs, universities, scientific research institutes, upstream and downstream suppliers and dealers [20], rival enterprises the influence of factors such as resource attributes of participating enterprises on the performance of co-innovation [21,22], and relevant case studies of co-innovation [23].

The Frequency and Centrality Analysis of Keywords
In order to understand the research hotspots of co-innovation, the time span was determined as "2010-2022" with a time interval of 1 year, and the keywords were extracted year by year to get the keyword co-occurrence map (figure 3), the high frequency keywords and their centrality of "Top30" about co-innovation research (table 2 and table 3). It can be seen that both domestic and foreign studies related to co-innovation show a fragmented multiple-wheel radial structure (domestic studies: N=212, E=261, Density=0.0117; foreign studies: N=160, E=286, Density=0.0225) with a low cohesive degree of keyword cooccurrence network, indicating that the current domestic and foreign studies on co-innovation are generally disperse. The top ten keywords in terms of frequency and centrality are "innovation chain", "industrial chain", "co-innovation", "capital chain", "collaborative innovation", "innovation ecosystem", "strategic emerging industry", "case research", "industry chain integration" and "key core technology". Among them, "innovation chain" and "industry chain" have the highest frequency and centrality, indicating that they are both the core topics and important pathways to studying innovation integration [19].
The top ten keywords in terms of frequency and centrality in foreign related studies are "strategy", "performance", "open innovation", "platform", "technology", "innovation", "collaboration", "co-innovation", "collaboration", "co-innovation", "model", "innovation ecosystem", the frequency and centrality of keywords are more even, reflecting the more decentralized topics of foreign co-innovation research. In particular, "platform" and "technology" have higher word frequency and lower centrality, indicating that platform and technology are more focused as co-innovation topics, but not considered as the mediating issues of co-innovation research.

Timezone Evolutionary Analysis of Keywords
To examine the evolution pattern of co-innovation research hotspots, the Timezone command is used to display the time zone diagram of keyword co-occurrence mapping. The keywords in the Timezone diagram indicate the time of their first appearance, and each later appearance is increased at the position of the first appearance, and the larger the circle indicates the more appearances, and the connection of nodes between different time zones shows the inheritance relationship of co-innovation research. As can be seen from figure 4, domestic co-innovation-related research can be roughly divided into 3 evolutionary stages. The first stage is the phenomenon discovery stage from 2011-2014, which mainly studies the integration of resource elements among different innovation subjects and the construction of their co-innovation platforms, although co-innovation in this stage is only regarded as a new manifestation of resource allocation under the open innovation paradigm, the boundary of innovation subjects has been initially broken [24,25]; the second stage is the diversified exploration stage from 2015-2019, in which scholars try to The third stage is the systematic research stage from 2020, driven by the "double-loop" strategy, scholars have been exploring with unprecedented enthusiasm on how to use the open innovation paradigm to explore the principle of co-innovation, integration mechanism, leading practices and governance measures [26][27][28]; The third phase is the systematic research phase since 2020. Driven by the "double-loop" strategy [29], scholars have conducted a series of fruitful researches on how to use the co-innovation paradigm to solve the difficult problems in China's science and technology innovation field [30,31], and have increasingly focused on the specific applications of the industrial Internet, blockchain and other technological tools in co-innovation [32].  [33], platform construction model [34], and enterprise initiative [35]. Some preliminary quantitative studies have also emerged, such as the impact of subject heterogeneity and network centrality on innovation performance in new open innovation platforms [36,37]. The second phase is the practical application phase from 2017-2022, in which foreign studies focus on how to apply the co-innovation paradigm to different countries, industries, and technological fields [38,39], and how to use digital tools to build and govern co-innovation and other specific practical issues [20].

The Emergent Strength Analysis of Keywords
The use of Citation Burst which detected the intensity of keyword emergence reflected and tracked the trend of research in this field. The minimum time unit was set to 1 year to generate a list of emergent keywords in domestic and foreign co-innovation research as shown in figure  6 and figure 7.   Figure 6 shows the emergent keywords of domestic research on co-innovation, and the red line segment represents the emergent year of the emergent words, indicating the growth point of research in a specific year. It can be found that domestic research started to study co-innovation as a new paradigm of open innovation in 2015, especially focusing on its significance to the development of strategic emerging industries and SMEs, which opened a multifaceted exploration stage of co-innovation research. With the formal introduction of the concept of "co-innovation" in 2020, related research entered the systematic research stage, and the frontier hotspots cover technical fields such as key core technologies, intelligent manufacturing, blockchain and policies such as Guangdong-Hong Kong-Macao Greater Bay Area, "four chains" integration, industrial policies.
The emergent keywords of foreign research on co-innovation, shown in figure 7, began with a focus on core large firms which broke open innovation organizational boundaries by providing open source technologies to SMEs with inter-firm collaborative technology innovation and its network ecology as a research hotspot. Frontier hotspots since 2020 include a focus on co-innovation outcomes such as technology, performance, and knowledge, as well as management, servitization, sustainability, and complexity, platform, and vision of the coinnovation process. Among them, the construction and governance of innovation platforms have become the frontier focus of research in terms of emergent intensity.

Conclusion
As the first systematic study on the literature of co-innovation at domestic and abroad, this study firstly identifies the concept and theoretical connotation of co-innovation based on the literature analysis, and bases on the deep content analysis of related literature, identifies 217 domestic and foreign literatures as the analysis objects, and summarizes the distribution of research themes of co-innovation, a new paradigm of open innovation. We found that domestic research mainly focuses on the macro perspective of deep integration of industry and innovation chains, while foreign research focuses more on micro issues of co-innovation practices such as open source technologies and new innovation platforms, which provide useful reference for the development of domestic integration innovation practices. Secondly, this study uses literature visualization analysis to sort out the domestic and foreign research hotspots and trends of co-innovation, and finds that compared with the achievements of foreign scholars in quantitative research and case studies, domestic relevant research is still limited to qualitative discussions at the theoretical level, which is difficult to meet the current needs of domestic co-innovation policy and practice development. Finally, oriented to make up for the deficiencies of existing research at home and abroad, this study will propose further development directions for co-innovation research in four aspects: mechanism of action, network model, empowerment mechanism and governance mechanism.
(1) Most studies have been conducted to study the mechanism of co-innovation among enterprises in the upper, middle and lower reaches of the industrial chain and the innovation chain in terms of basic research, technology development and commercial industrialization, especially focusing on the internal logic of deep integration and synergistic upgrading between the industrial chain and the innovation chain. However, in the horizontal perspective, it is not clear how the efficient integration and fusion of innovation factors such as information, knowledge, capital, talents and services should be realized among large and small enterprises, state-owned enterprises and private enterprises? How to measure the co-innovation effect emerging through co-innovation factors among the main entities? What are the roles of government, intermediaries, financial institutions, users, etc. in the co-innovation cooperation network with enterprises as the core, and what are their effects on the co-innovation effect? Future research can find ways to measure the integration of subjects from the goal synergy  dimension and interest synergy dimension among co-innovation subjects, and find ways to measure the smoothness of co-innovation elements from the openness dimension and sharing dimension of co-innovation elements; integrate the two to achieve quantitative measurement of the co-innovation effect of inter-subject innovation elements.
(2) After nearly two years of practice, co-innovation has developed from the initial "double chain" integration process of industry chain and innovation chain to the "four chain" integration process of industry chain, innovation chain, capital chain and talent chain, which means co-innovation will present a more complex and diversified network. This means that the innovation will present a more complex and diversified network mode. However, the re- search on the existing co-innovation network model is still very limited, what are the main paths of co-innovation network formation and operation mechanisms? What is the position of open innovation platforms in the network? How does the co-innovation effect play out? What are the specific factors that affect the effectiveness and stability of co-innovation network? All these questions need to be considered. Future research can seize the opportunity of the current booming domestic co-innovation practice, base on the principle of the mechanism of co-innovation to achieve scientific and technological self-reliance and self-improvement, and identify the effective organization mode of co-innovation network from various perspectives such as different regions, different industries and different technological fields.
(3) Core firms are in a dominant position in co-innovation due to their resource characteristics and market position, and have a significant empowering effect on both innovation agents in co-innovation networks and their innovation activities. However, there is a lack of theoretical consensus on the enabling mechanism of core firms in existing studies. What are the paths and mechanisms for core enterprises to empower other co-innovators? How do the resource characteristics and market position of core enterprises affect their ability and level of empowerment to other co-innovators? What are the situational factors that influence the enabling role of core enterprises? Future research should first clarify the driving factors of co-innovation carried out by core enterprises and various innovation subjects, discuss the formation conditions of co-innovation field around the common technologies among coinnovation subjects, and propose the main co-innovation mechanism for the empowerment role of core enterprises.
(4) With the wide application of blockchain technology, the research of using distributed ideas to govern the innovation behavior of various co-innovation subjects has attracted much attention. However, opening the governance dilemma of co-innovation requires not only mastering technical means, but also exploring mechanism principles, such as how should co-innovation in different regions, industries or technology scenarios be designed and selected for governance mechanisms? Future research needs to differentiate governance models according to specific scenarios of co-innovation, such as the cooperation relationship between co-innovation subjects, which should be governed differently according to the position relationship of each subject in the industrial or technological chain. Secondly, since co-innovation is still essentially an open innovation paradigm, external heterogeneous subjects such as government, universities and research institutions, intermediaries, financial institutions, and users also have interactive influence on its co-innovation effect, and how to strengthen the governance of external influencing factors to guarantee co-innovation subjects to achieve their innovation goals becomes an important issue. Finally, in the context of the rapid development of digital technologies and industries such as big data, artificial intelligence, blockchain, and cloud computing, digitalization is both the means and the object of governance of co-innovation.