Introduction

Innovation is essential for sustainable economic growth (Lucas, 1988; Romer, 1986). Moreover, innovation cooperation can further increase knowledge diversity and stimulate creativity (Fleming et al., 2007; Reagans and Zuckerman, 2001) to provide an inexhaustible impetus for the prosperity and development of a country or region. At present, the world’s innovation landscape is constantly reshaping, emerging countries are continuously improving their innovation capabilities, and the demand for innovation cooperation between countries is also increasing. In the context of globalization, key innovation elements such as talent, knowledge, and technology are rapidly flowing around the world, providing a good opportunity for international innovation cooperation. Many studies document that innovation cooperation between countries can not only improve the value and quality of innovation results (Bercovitz and Feldman, 2011; Singh and Fleming, 2010) but also broaden the channels for underdeveloped countries to achieve technological catch-up and surpass their targets through international knowledge spillovers (Giuliani et al., 2016). Strengthening international innovation cooperation and actively integrating into the global science and technology innovation network are undoubtedly of great significance for enhancing the innovation strength of countries, especially developing countries, and for thereby promoting healthy and sustainable economic development.

The Belt and Road Initiative (hereafter referred to as the BRI) provides a broader space and platform for innovation cooperation between countries. The BRI is a road of innovation. In 2016, the Special Plan for Promoting the Scientific and Technological Innovation Cooperation of the Belt and Road Construction was jointly issued by the Ministry of Science and Technology and three other ministries of China. It aims to strengthen the exchange of scientific and technological talent between countries, build an innovation cooperation platform, and formulate and implement targeted scientific and technological innovation cooperation policies to promote sustainable development and common prosperity. In 2019, China, Thailand, Russia, etc., jointly signed the Cooperation Initiative on the Silk Road of Innovation, promising to further deepen pragmatic cooperation in the field of scientific and technological innovation. Furthermore, the Chinese government has actively called on enterprises, universities, research institutions, and other innovative entities to fully participate in international innovation cooperation. For instance, the Chinese Academy of Sciences launched science and education development projects in developing countries since 2013 to cultivate more than 5000 professional and technical talents for countries along the Belt and Road routes. Technological innovation cooperation is the core content and important driving force of BRI construction. Therefore, it has important theoretical value and practical significance for examining the BRI’s economic and social effects from the perspective of international innovation cooperation and exploring the interactive relationship between China and BRI partner countries (i.e., countries that have signed BRI cooperation documents).

Since the BRI was proposed, it has attracted widespread attention from scholars. They have carried out systematic research from the perspectives of foreign investment (Herrero and Xu, 2017; Wiederer, 2018), energy efficiency (Peng et al., 2021), export trade (Ramasamy and Yeung, 2019), financial cooperation (Sun and Hou, 2019), global value chain optimization (Dai and Song, 2021), etc., and achieved valuable research results. However, although the BRI has provided many conveniences for innovation cooperation among countries, there are few studies concerned with whether it can promote international innovation cooperation, and the motivation and internal mechanisms behind the question.

Based on the above analysis, the relationship between the BRI and international innovation cooperation is explored next. The top 80 global countries in innovation capacity are taken as the research sample. Whether the country officially signed BRI cooperation documents with China is regarded as a quasi-natural experiment. From the perspectives of the initiator (China) and the partners (BRI partner countries), we use the difference-in-differences (DID) method to test whether the BRI can promote innovation cooperation between them. The empirical results show that the BRI indeed promoted innovation cooperation to a certain extent. The promotion effect is more obvious for partner countries with better economic foundations. Specifically, it significantly increased the proportion of cooperative patents in China’s total patents, indicating that the Chinese government is more motivated and willing to have more resources to cooperate with BRI partner countries. Furthermore, the mechanism tests show that shortening institutional distance, strengthening the exchange of scientific and technological talent, and stimulating cultural differences are important mechanisms promoting innovation cooperation. Although the BRI did not significantly increase the proportion of cooperative patents in partner countries’ total patents, it effectively improved their innovation foundations and capabilities.

Our marginal contributions are as follows: first, investigating the BRI’s economic and social effects from the perspective of international innovation cooperation broadens the research scope of the BRI; second, the impact of the BRI on the initiator and partners is discussed, and the impact differences between them are compared. Moreover, the reasons behind it are explained. Third, the mechanisms of the BRI affecting innovation cooperation are explored from the aspects of institutional distance, cultural distance, and the exchange of scientific and technological talent. The positive effect of the BRI on the innovation foundations and capabilities of partner countries is examined.

The remainder of the paper is organized as follows. Section “Literature review and research hypotheses” gives the literature review and research hypotheses. Section “Research design” describes the research design, mainly introducing the model design, variables, and data sources. Section “Empirical results” analyzes the empirical results. Section “Mechanism analysis” tests the impacting mechanisms. Section “Further analysis: The BRI and BRI partner countries' innovation capabilities” further explores the impact of the BRI on BRI partner countries’ innovation capabilities. Section “Discussion” provides further discussion. The last section summarizes the main conclusion and policy implications.

Literature review and research hypotheses

Literature review

There are mainly two strands of literature closely related to this study. The first strand of literature examines the socio-economic effects of the BRI. Some of them mainly focus on the impact of the BRI on China’s economic development. They found that it significantly increases China’s potential for outward FDI and exports (Shao, 2020; Yu et al., 2020), enhances the technological innovation capabilities of domestic enterprises through market competition and capacity utilization (Wu and Si, 2022), creates more job opportunities for China (Liao et al., 2021), and improves the quality of economic growth in Chinese cities (Kong et al., 2021). Additionally, some also found that the BRI causes more “hostility” to China’s overseas investments (Jin et al., 2021) and an increase in carbon emissions (Xiao et al., 2023).

Other literature focuses on the impact of the BRI on the partner countries and other economies. They found that it improves the business environment of the BRI partner countries (Chen et al., 2020), and significantly enhances their international trade status and exports (Ramasamy and Yeung, 2019), thereby promoting their actual income and economic performance (Bird et al., 2020; Yang et al., 2020; Ma, 2022). Additionally, the BRI also brings closer communication between countries (Dang and Zhao, 2020), and improves trade integration level (Han et al., 2018) and energy efficiency (Peng et al., 2021). However, some scholars argue some negative impacts of the BRI on other countries. For instance, Overholt (2015) considered China’s expansion of outward FDI aims at transferring excess production capacity overseas; Howard and Howard (2016) deemed that China transfers some industries with high pollution and high-energy consumption to the partner countries; Bruni (2019) showed that the BRI exacerbates partner countries’ income inequality.

The second strand of literature explores the influencing factors of innovation cooperation. Innovation cooperation refers to the joint acquisition or creation of knowledge and technology, which can enhance the absorption capacity and innovation performance of innovation entities (Fleming et al., 2007; Mendi et al., 2020). Hence, scholars mainly explore the influencing factors of innovation cooperation from the perspectives of R&D costs, external environment, geographical location, and partner types. They found that when R&D costs and innovation difficulty are high, innovation entities tend to prefer innovation cooperation (Becker and Dietz, 2004; Marchi et al., 2022). Enterprises located in technology parks and those with low environmental uncertainty are more likely to choose innovation cooperation (Urriago et al., 2016; Liu et al., 2023). Faria et al. (2010) and Liu et al. (2023) emphasized the importance of partners and found that different partners have a significant impact on the probability and outcome of innovation cooperation.

International innovation cooperation is also influenced by institutional and cultural distances between countries. Among them, institutional distance refers to the differences in laws, regulations, policy environments, and market rules between different countries (Song et al., 2011), while cultural distance refers to the differences in values, thinking patterns, customs, and beliefs between different countries (Estrin et al., 2010). Scholars showed that both formal and informal institutional distances have a significant impact on innovation performance and cooperation (Wang and Chuang, 2020; Wang et al., 2023), and cultural distance has become a key factor affecting innovation transfer among multinational enterprises (Ansari et al., 2014). Jensen and Szulanski (2004) and Alofan et al. (2020) argued that the increase in cultural distance between countries significantly suppresses knowledge spillovers and technology transfer, thus exerting a negative impact on innovation cooperation.

To sum up, although many scholars have investigated the social and economic effects of the BRI on various countries, few have paid attention to its impact on innovation cooperation among countries. Meanwhile, in the investigation of the influencing factors of innovation cooperation, there is also little literature on the impact of major international initiatives on innovation cooperation between countries. In view of this, this study empirically explores the impact of the BRI on innovation cooperation between countries and the mechanisms, so as to expand and supplement the aforementioned two strands of literature.

Research hypotheses

Technological innovation cooperation is an important force in promoting the BRI toward high-quality development. Chinese President Xi Jinping reiterated at the 2nd Belt and Road Forum for International Cooperation that the Technology and Innovation Cooperation Action Plan is one of the most critical parts of the Belt and Road Initiative. Additionally, with increasing scientific and technological innovation strength, China has the basic conditions to participate in and lead international scientific and technological innovation cooperation. Statistics indicate that in 2019, the number of PCT international patent inventions in China exceeded 58,000, second only to the United States; the number of published scientific papers in China was first in the world, and the number of high-quality international scientific papers was second in the world. China also pays high attention to international scientific and technological innovation cooperation. In 2017, the number of international coauthored papers in China was 97,400, accounting for 27.0% of the total number of published scientific papers. China’s international scientific and technological innovation continues to increase. It can be said that the BRI has opened up space for scientific and technological innovation cooperation between China and other countries and deepened cooperation through political mutual trust, talent exchanges, cultural tolerance, etc., to jointly solve the technical problems of economic development.

First, the BRI can promote macro-policy coordination, reduce policy barriers, and shorten institutional distances between China and BRI partner countries, thereby promoting their cooperation in science and technology innovation. Generally, the expansion of institutional distance has a negative impact on innovation cooperation (Li et al., 2014). Specifically, (i) large institutional distance increases the cost of cooperation between parties. They need to spend more time and energy to understand and adapt to each other’s institutional environment, thereby increasing the difficulty and uncertainty of innovation cooperation (Banalieva and Dhanaraj, 2013). (ii) Large institutional distance makes it difficult to form uniform rules and procedures within the innovation group, and the innovation output is also likely to deviate from the policy orientation and market preference of the host countries (Li et al., 2014). (iii) Enterprises are one of the most important subjects of technological innovation, and their transnational commercial activities are also the main carriers of innovation cooperation. However, multinational companies prefer to conduct investment and business cooperation in countries with similar systems to reduce transaction costs and investment risks, thereby obtaining higher economic returns (Wang et al., 2016). The BRI effectively shortens the institutional distance between China and BRI partner countries. Policy communication and mutual trust are the BRI’s important elements. China and partner countries jointly formulated cooperation plans and maintained communication about development strategies and implementation policies, providing institutional guarantees for cooperation and exchanges.

Second, as a national-level strategic agreement, one of the goals of the BRI is to jointly establish a community of common destiny with cultural tolerance. McKercher and Chow (2001) showed that people are more willing to engage in cultural and knowledge-related activities in areas with larger cultural differences. Furthermore, compared to cultural convergence, cultural divergence is more effective in promoting innovation cooperation, which can provide more exchanges and collisions of ideas (Vaara et al., 2012). However, due to the trust and communication barriers brought about by cultural distance (Beugelsdijk et al., 2014), it is difficult to play a role in promoting innovation cooperation. The BRI can effectively break these barriers. Various innovative entities cooperate under the guidance of the government and are endorsed by national credibility, breaking the trust barriers caused by cultural differences. With increasingly close cultural exchanges, talent exchanges, and academic exchanges, the cooperative relationship under different cultural backgrounds has also been further consolidated to give play to the positive impact of cultural differences on innovation cooperation.

Finally, the BRI provides a good opportunity for the exchange of scientific and technological talent between countries, thereby laying a talent foundation for their innovation cooperation. Talent is the core determinant of innovation activities and capabilities. Talent exchange can enhance communication and trust and increase the knowledge stock of innovative entities (Johnson, 2010), thus promoting innovation cooperation. People-to-people communication is the core to the long-term sustainability of the BRI, and talent exchange is one of the most important areas. The BRI provides more convenient conditions and policy support for talent exchange. For instance, in July 2016, the Ministry of Education of China announced that China would subsidize 10,000 new students from countries along the Belt and Road routes to study in China or other countries each year for the next 5 years and send 2500 students to study in countries along the Belt and Road routes each year in the next 3 years.

Based on the above analysis, the following four research hypotheses are proposed:

Hypothesis 1: The BRI can promote innovation cooperation between China and BRI partner countries.

Hypothesis 2: The BRI can shorten the institutional distance, thereby promoting innovation cooperation.

Hypothesis 3: The BRI can give full play to the positive effect of cultural distance on innovation cooperation.

Hypothesis 4: The BRI can enhance talent exchange, thereby promoting innovation cooperation.

Research design

Sample

The top 80 global countries in innovation capability released by the World Intellectual Property Organization are selected as the research sample herein. The reasons are that on the one hand, the GDP of these countries accounts for more than 87% of the world’s total, and their total number of multinational cooperative invention patents accounts for more than 97% of the world, while the number of multinational cooperative patents in the remaining countries is extremely small, especially the number of cooperative patents with China, which is almost zero; on the other hand, the sample countries cover Asia, Europe, North America, Oceania, Africa and other regions, including developed and developing countries, which can fully reflect the innovation cooperation between countries. The BRI was formally proposed in 2013. Considering the availability of the required data, we finally selected the 5 years before and after the BRI was proposed as the sample period, i.e., 2008–2018. Then, since this paper studies the level of innovation cooperation between China and other countries, China and Hong Kong are excluded. Due to missing data, Montenegro, Serbia, and Bulgaria are also removed. Ultimately, 825 country-year observations were obtained.

Model setting

To effectively identify whether participation in the BRI (i.e., signing BRI cooperation documents with China) can promote international innovation cooperation, the DID method is employed to evaluate the effect of the BRI based on the literature (Yu et al., 2020; Jiang et al., 2021; Lee and Wang, 2022). This method has been widely recognized and applied because it can better identify causal effects according to the existence of a policy and the difference-in-differences before and after the policy (Yu et al., 2020). Since the BRI partner countries and China signed BRI cooperation documents in different years, the following staggered DID model is established:

$${\rm {INCO}}_{{\rm {ct}}} = \alpha _0 + \alpha _1{\rm {Treat}}_{\rm {c}} \times {\rm {Post}}_{\rm {t}} + \beta X_{{\rm {ct}}} + \mu _{\rm {t}} + \omega _{\rm {c}} + \sigma _{\rm {{ct}}}$$
(1)

where c and t represent the country and the year, respectively; Treat is a dummy variable that distinguishes the treatment group from the control group. When a country formally signed BRI cooperation documents with China, it equals 1; otherwise, it equals 0. Post is a time dummy variable. When a country signed the cooperation documents in and after the year, it equals 1; otherwise, it equals 0. Xct denotes a series of control variables at the national level, including economic level, industrial structure, labor structure, urbanization level, FDI level, etc.; μt and ωc represent the year and country fixed effects, respectively; σct is the random disturbance term. Due to the existence of multicollinearity, the treatment variable (Treat) and country fixed effects, time variable (Post), and year fixed effects cannot be included in the model at the same time, so they are omitted.

Variables and data sources

Explained variable

The level of international innovation cooperation. Patents can directly reflect innovation achievements and can be used to accurately and effectively measure the national innovation level (Popp, 2006). Hence, following Giuliani et al. (2016), we adopt the number of joint patents between countries to measure the level of innovation cooperation between them. The patent data are derived from WIPO’s PCT international patent database, which collects relevant information about PCT international patent applications from countries around the world. This database can effectively avoid the data deviation of a single national patent office and the data duplication statistics of different patent offices. We use the advanced search method to manually collect the number of patents jointly invented by China and other countries from 2008 to 2018 and the total number of invention patents of each country from 2008 to 2018 according to the nationality of the patent inventor. Furthermore, to reveal the impact of the BRI on innovation cooperation in a more detailed and accurate manner, following Giuliani et al. (2016), we divide the number of joint patents by the total number of invention patents in China and other countries and then multiply it by 100 to construct the innovation cooperation level variables HOMIC and HOSIC. The two variables have two advantages. On the one hand, compared with the absolute value of cooperative patent data, the relative value is more accurate and effective because it is not easily affected by the total number of national innovation patents, national innovation capabilities, economic level, and other factors. On the other hand, the national innovation cooperation level is measured from both parties: China and other countries. It is possible to more systematically and comprehensively examine the impact of the BRI on innovation cooperation between them.

Core explanatory variable: Treat ×Post

The staggered DID model is used herein. Treat × Post is the interaction item of the treatment variable (Treat) and the time variable (Post). Therefore, when country c officially signed BRI cooperation documents with China in year t, Treat × Post equals 1; otherwise, it equals 0.

Control variables

Following the existing studies (Yu et al., 2020; Nugent and Lu, 2021; Jin et al., 2021), we select the following five national-level control variables to ensure the validity of the empirical results: (i) economic scale (PGDP), expressed by GDP per capita; (ii) industrial structure (ADV), expressed by the proportion of manufacturing added value in GDP; (iii) human capital level (LABOR), expressed by the proportion of people aged 15–64 in the total population; (iv) urbanization level (URBAN), expressed by the proportion of the urban population in the total population; and (v) openness level (OPEN), expressed by the amount of FDI. The above data are all derived from the World Bank Open Data. Table 1 gives their descriptive statistics.

Table 1 Descriptive statistics of variables.
Full size table

Empirical results

Baseline regression

Table 2 reports the baseline regression results. Specifically, Column (1) shows the impact of the BRI on the level of innovation cooperation for China (hereafter referred to as HOMIC). The estimated coefficient of Treat × Post is significantly positive at the 1% level, indicating that the BRI indeed significantly improved the HOMIC, i.e., the proportion of the number of cooperative patents between China and the BRI partner countries in China’s total patents; Column (2) reports the impact of the BRI on the level of innovation cooperation for the BRI partner countries (hereafter referred to as HOSIC). The estimated coefficient of Treat × Post is not significant, indicating that the BRI did not significantly promote the HOSIC, i.e., the proportion of the number of cooperative patents between China and the BRI partner countries in the BRI partner countries’ total patents. Furthermore, considering the lag of the policy and the delay of patent applications, the coefficient of the core explanatory variable Treat × Post is re-estimated by taking its lag term. Columns (3) and (4) report the regression results, showing that the BRI only significantly increased the HOMIC but had no significant impact on the HOSIC. The reason is that for HOMIC, as the BRI’s initiator, China naturally has stronger motives and incentives to promote its cooperation with the signatories of the BRI (Nugent and Lu, 2021). Under the guidance of the Chinese government, Chinese companies favor the signatories of the BRI when investing or cooperating with other countries (Yu et al., 2020) to improve HOMIC; for HOSIC, as of 2018, most of the countries that have signed BRI cooperation documents with China are developing or underdeveloped countries with weak economic and innovation foundations. A large amount of resource input is the basis and prerequisite for innovative activities (Huang et al., 2019). Therefore, their weak economic and innovation foundations become the most important factors restricting the improvement of the level of cross-border innovation cooperation (Manso, 2011). This may also be an important reason why their level of innovation cooperation with other countries is not significantly sensitive to external policy shocks.

Table 2 Baseline regression results.
Full size table

To verify the above conjecture, the difference-in-differences-in-differences (DDD) model is established to test whether the BRI promoted innovation cooperation between China and countries with a solid economic foundation. In this regard, a dummy variable Income is set to measure the economic basis. Specifically, following Bolarinwa and Akinlo (2021) and using data from the World Bank, a country with a per capita national income greater than or equal to US$3896 is defined as a country with a solid economic foundation, and its Income equals 1; otherwise, it is defined as a country with a weak economic foundation, and its Income equals 0. The DDD model is built as follows (Qi et al., 2021):

$$\begin{array}{l}{\rm {INCO}}_{{\rm {ct}}} = \alpha _0 + \alpha _1{\rm {Treat}}_{\rm {c}} \times {\rm {Post}}_t \times {\rm {Income}}_{{\rm {ct}}} + \alpha _2{\rm {Treat}}_{\rm {c}} \times {\rm {Post}}_{\rm {t}} + \alpha _3{\rm {Treat}}_{\rm {c}}\\ \qquad\qquad\quad\times \,{\rm {Income}}_{\rm {{ct}}} + \alpha _4{\rm {Income}}_{{\rm {ct}}} \times {\rm {Post}}_t + \beta X_{{\rm {ct}}} + \mu _{\rm {t}} + \omega _{\rm {c}} + \sigma _{{\rm {ct}}}\end{array}$$
(2)

If the estimated coefficient of Treat × Post × Income is significantly positive, the promoting effect of the BRI on international innovation cooperation with a solid economic foundation country is more significant. Columns (5) and (6) of Table 2 report the regression results. In Column (5), the estimated coefficient of Treat × Post × Income is significantly positive, indicating that as the countries’ economic level increased, the BRI became increasingly effective in promoting HOMIC; in Column (6), the explained variable is HOSIC, and the estimated coefficient of Treat × Post × Income is also positive but not significant. The above results further illustrate that the effect of the BRI on promoting innovative cooperation is more pronounced in regions with better economic development foundations.

Parallel trend tests

The DID model is employed to test the impact of the BRI on innovation cooperation between China and BRI partner countries. An important prerequisite for using this model is that the parallel trend assumption holds prior to the BRI. According to the existing studies (Du and Zhang, 2018; Moser and Voena, 2009), the interaction term between the dummy variable of signing BRI cooperation documents (Treat) and the year dummy variable (Year) is introduced in the model, and the year before the BRI is taken as the benchmark for regression testing (as shown in Table 3). pre and post represent the interaction items before and after the BRI, respectively. Additionally, to prevent the existence of autocorrelation factors in time series in different countries in different years during a long time window, standard errors are clustered at the country and year joint level (Bo, 2020). Table 3 shows that for HOMIC, the coefficients of the interaction terms before the BRI are not significant and negative, and the coefficients of the interaction terms after the BRI are significantly positive; for HOSIC, the coefficients of the interaction terms before and after the BRI are not significant. This shows that the parallel trend assumption holds, proving the validity of the model.

Table 3 Parallel trend tests.
Full size table

Robustness tests

The previous empirical results show that the BRI indeed promoted innovation cooperation between China and BRI partner countries, which is mainly reflected in its significant increase in the number of cooperative patents as a proportion of China’s total patents. However, the proportion of cooperative patents in BRI partner countries’ total patents did not increase significantly. To further ensure the robustness and reliability of the empirical conclusion, we perform a series of robustness tests, specifically redefining the BRI partner countries, removing the special years and countries, eliminating the interference of other policies, carrying out placebo tests and using the PSM-DID method.

Redefining BRI partner countries

In the above baseline regression, the countries that have officially signed BRI documents with China are defined as BRI partner countries, and the policy shock time is defined as the year when the cooperation documents were signed. However, some scholars define the countries along the Belt and Road routes as BRI partner countries and set the time of policy shock to 2013 (Kong et al., 2021; Jiang et al., 2021). The reasons that the BRI was formally proposed by China in 2013 to establish friendly and win‒win bilateral and multilateral mechanisms with countries around the world. When the BRI was put forward, the countries along it were the first to be affected, and the Chinese government and enterprises also took the lead in cooperation and exchanges with them (Kong et al., 2021). Therefore, we redefine the countries along the Belt and Road routes as the treatment group and set the policy shock time to 2013. Columns (1) and (2) of Table 4 report the regression results. For HOMIC, the estimated coefficient of the new core explanatory variable (Treat × Post2) is significantly positive at the 1% level; however, for HOSIC, the estimated coefficient of Treat × Post2 is still not significant, which is consistent with the previous empirical conclusion.

Table 4 Robustness tests.
Full size table

Removing the special years

In the baseline regression, BRI partner countries are those formally signing cooperation documents with China. However, when the BRI was proposed, although some countries had not formally signed cooperation documents with China, they may have been affected by the BRI (Li and Li, 2020). To avoid its influence on the empirical conclusion, 2013 (the year when the proposal was proposed) and 2014 (considering the policy lag) are removed sequentially for reregression. The results of Columns (3)–(6) in Table 4 show that the BRI still significantly promoted HOMIC but did not obviously promote HOSIC, again supporting the results of the baseline regression.

Removing the special countries

The number of patents jointly invented by countries and China is taken as the research object to examine the impact of the BRI on international innovation cooperation. However, the number of joint invention patents of some countries with China during the entire sample period is always zero. The possible reasons are that these countries have a weak innovation foundation, their total innovation output has always been at a very low level, or the channel for innovation cooperation between them and China has not been opened due to the intervention of other factors. Including these countries in the research sample may cause certain biases. In this regard, countries with zero patents in cooperation with China from 2008 to 2018 are removed from the regression. The results of Columns (7) and (8) in Table 4 show that the significance and sign of the estimated coefficients of Treat×Post are basically consistent with the baseline regression.

Eliminating the interference of other policies

When examining the impact of the BRI on innovation cooperation between China and BRI partner countries, it is necessary to avoid the influence of other policies in the same period (Kong et al., 2021). The China–Central and Eastern Europe ‘16 + 1’ cooperation framework established by China and 16 Central and Eastern European countries in 2012 may interfere with the impact of the BRI (Dai and Song, 2021). On the one hand, this cooperation system was established in 2012, only one year after the proposal of the BRI. On the other hand, Central and Eastern Europe is one of the regions closest to the BRI. Both the China–Central and Eastern Europe ‘16 + 1’ and the BRI emphasized in-depth cooperation in technological innovation, infrastructure construction, and investment. In addition, the distribution of the 16 Central and Eastern European countries in the treatment group and the control group is also different. It is necessary to remove them for regression to eliminate the possible interference caused by the China–Central and Eastern Europe ‘16 + 1’ cooperation framework. Columns (9) and (10) of Table 4 report the regression results. We can see that the results are consistent with the above baseline analysis. This also means that after eliminating the possible interference of the China–Central and Eastern Europe ‘16 + 1’ cooperation framework, the research conclusion is still robust.

Placebo tests

To further test the reliability of the empirical conclusion, a false treatment group is constructed for placebo tests. The countries that did not participate in the BRI at the end of 2018 are regarded as the false treatment group, and 2013 is used as the external shock year (Dai and Song, 2021). Since the level of innovation cooperation of nonpartner countries cannot be affected by the BRI, if they are used as the treatment group and the regression estimation results are also significantly positive, then the BRI did not have a real impact on innovation cooperation. Columns (11) and (12) of Table 4 report the regression results. The estimated coefficients of Treat × Post are no longer significantly positive, which supports the baseline regression conclusion. It is worth mentioning that for HOMIC, the estimated coefficient of Treat × Post is significantly negative at the 1% level. A possible explanation is that after the BRI was put forward, the Chinese government and enterprises preferred BRI partner countries when cooperating with other countries. In contrast, under the premise of limited resources and projects, innovative cooperation activities between China and nonpartner countries may be squeezed out (Li and Li, 2020). Therefore, the estimated coefficient of Treat × Post is significantly negative.

PSM-DID method

To further alleviate the endogeneity problem caused by sample selection bias, the method of combining propensity score matching and difference-in-differences (PSM-DID) is used for regression. One advantage of this method is to ensure that the basic characteristics of the treatment group and the control group were not significantly different before the policy was implemented (Jiang et al., 2021; Liu et al., 2020). Columns (13) and (14) of Table 4 report the regression results. We can see that the results are consistent with the previous baseline regression results.

Mechanism analysis

The previous results confirm that the BRI indeed significantly promoted innovation cooperation between China and BRI partner countries. Specifically, it increased the number of joint invention patents as a proportion of China’s total invention patents. Therefore, what are the specific mechanisms? Next, the mechanisms are analyzed from three aspects: institutional distance, cultural distance, and talent exchange.

Institutional distance

The BRI may shorten the institutional distance between two countries, thereby promoting innovation cooperation. Li et al. (2014) showed that a large institutional distance has a negative impact on innovation cooperation between countries. The reasons are that the expansion of institutional distance not only increases the cost and difficulty of cooperation (Banalieva and Dhanaraj, 2013) but also makes innovation output deviate from market demand (Li et al., 2014), making it difficult to obtain expected economic returns. The BRI may effectively shorten the institutional distance between China and BRI partner countries. Officially signing BRI cooperation documents means that the consensus between the two parties is further deepened at the national strategic level. They will continue to communicate and adjust policies to provide a better institutional environment and cooperation platform for more comprehensive cooperation.

Therefore, based on relevant studies (Guo and Tu, 2021; Wu and Pan, 2019), worldwide governance indicators (WGI) are used to calculate the institutional distance between countries. The specific formula is as follows:

$${\rm {SD}}_{{\rm {c}}t}=\frac{1}{6}\mathop{\sum}\limits_{k=1}(I_{kt}-I_{{\rm{c}}kt})^2/V_{Ik}$$
(3)

where IKt and Ickt represent the scores of China and country c on institutional dimension K, respectively; VIK represents the variance of the scores of all sample countries; and K represents the six dimensions of WGI. The data are derived from the World Bank WGI. A greater SD means a longer institutional distance. Columns (1) and (2) of Table 5 report the regression results. We can see that the estimated coefficient of the core explanatory variable (Treat × Post) is significantly negative regardless of whether the control variables are added. This indicates that after signing the BRI, the institutional distance between China and partner countries has been significantly shortened, providing a good institutional environment for innovation cooperation.

Table 5 Mechanism tests.
Full size table

Cultural distance

The BRI can better bring into play the promotion effect of cultural distance on innovation cooperation, thereby improving HOMIC. Regarding the impact of cultural distance on innovation cooperation, the academic community has not yet reached an agreement. Some have argued that a large cultural distance makes it difficult for innovative entities with different cultural backgrounds to establish reliable trust relationships (Beugelsdijk et al., 2014) and even cause cultural conflicts, which is not conducive to the maintenance of cooperative relationships (Chang et al., 2012). Other studies have opposed this view. They considered that the differences in thinking and the complementarity of knowledge brought about by cultural distance are more likely to stimulate innovative inspiration and thinking (Vaara et al., 2012), which is conducive to improving the level of innovation cooperation. Following Liu et al. (2021), we use the KSI index provided by Kogut and Singh (1988) to measure cultural distance to test the impact of cultural distance on innovation cooperation. The specific formula is as follows:

$${\rm {CD}}_{\rm {c}} = \frac{1}{6}\mathop {\sum}\limits_{K = 1} {\left( {C_K - C_{{\rm {c}}k}} \right)^2/V_{CK}}$$
(4)

where CK and Cck represent the scores of China and country c on cultural dimension K, respectively; VCK represents the variance of the scores of all sample countries; and K represents the six dimensions of the KSI index. The data are derived from the Geert Hofstede website. In addition, considering that our research data are panel data, the interaction term between the cultural distance variable and time variable is constructed to form panel data (Nunn and Qian, 2014). First, the full sample data are used to test the impact of cultural distance on international innovation cooperation (Column (3) in Table 5). The results show that the coefficient of cultural distance is positive but not significant, indicating that cultural distance promoted innovation cooperation among countries, which is also consistent with the relevant literature (Vaara et al., 2012). Cultural differences can improve the level of innovation cooperation, but there are currently some obstacles preventing the promotion effect. To test whether the BRI can break these obstacles and better play the role of cultural distance in promoting innovation cooperation, subsample regression is performed according to whether or not to participate in the BRI. Columns (4) and (5) of Table 5 report the regression results. They show the results with nonpartner and partner countries as the research sample. We find that under the premise that other variables remain the same, cultural distance is significantly positive in the sample of BRI partner countries, showing that the BRI enhanced trust and cultural exchanges among partner countries and broke the natural barriers of cultural distance so that the promoting effect of cultural diversity on innovation cooperation between countries is revealed. The reasons are that the BRI is strategic cooperation at the national level, which can provide a trust guarantee for cross-border cooperation with government credibility, build a solid bridge for cooperation between innovative entities under different cultural backgrounds, and break the barriers to cooperation caused by cultural distance to better play its role in promoting innovation cooperation between countries.

Talent exchange

The BRI can also promote the exchange of talent between countries, thereby enhancing the level of innovation cooperation between them. Talent is the most fundamental factor determining the innovation capability of an enterprise, region, and country (Mannasoo et al., 2018; David and Kamel, 2009). International talent exchange can obviously promote the dissemination of technology and knowledge among different countries and lay a talent foundation for innovative cooperation between countries. Therefore, to test whether the BRI significantly promoted the exchange of talent between China and BRI partner countries, the number of Chinese students studying abroad and the number of foreign students in China as proxy variables of talent exchange (denoted as Talex1 and Talex2, respectively) are selected for regression. Columns (6) and (7) of Table 5 report the regression results. We can see that after joining the BRI, the number of personnel exchanges between China and partner countries increased significantly. Talent is the foundation of innovation, and exchanges and cooperation between talent can significantly improve the level of innovation cooperation among countries.

Further analysis: The BRI and BRI partner countries’ innovation capabilities

The above results show that the BRI significantly promoted HOMIC but did not significantly promote HOSIC. The possible reason is that the innovation foundations of some BRI partner countries are relatively weak. Did the BRI help increase the innovation expenditure of BRI partner countries and improve their innovation capabilities? This problem needs to be further analyzed. Next, we empirically explore the impact of the BRI on the innovation capabilities of BRI partner countries.

The previous results show that for BRI partner countries, the BRI did not significantly promote the ratio of the number of cooperative patents to partner countries’ total patents. The possible reason is that the innovation foundations of these countries are relatively weak. The promotion effect of the BRI may be mainly reflected in improving their innovation foundations and innovation capabilities. To test this conjecture, we empirically test whether partner countries’ innovation capabilities significantly improved after joining the BRI. Existing studies (Du et al., 2019; Kimpimäki et al., 2021) have shown that the total number of international innovation patents, the number of scientific and technical journal papers, and the ratio of R&D expenditure to GDP can be used to effectively measure a country’s innovation foundation and capabilities. Columns (1)–(7) of Table 6 report the regression results. We can see that after considering innovation output and the lag of policy implementation, the total number of invention patents and the number of scientific and technical journal papers in the partner countries significantly improved compared to before joining the BRI. Meanwhile, the BRI also significantly increased the proportion of BRI partner countries’ R&D expenditures in GDP, indicating that this promotion effect is timely without lag. These results show that after joining the BRI, the partner countries significantly improved their innovation input and output (the number of patents and scientific and technical papers), which means that the innovation capacities and foundations of these countries significantly improved. The BRI realized the exchange and integration of commodities, technology, capital and personnel between China and BRI partner countries, significantly increased the investment and innovation cooperation activities of Chinese enterprises and scientific research institutions in BRI partner countries (Jiang et al., 2021; Jin et al., 2021), and promoted innovation investment and technological progress in underdeveloped countries. The above results show that the BRI had obvious positive externalities. It not only promoted innovation cooperation but also had a significant role in promoting the innovation foundations and innovation capabilities of BRI partner countries.

Table 6 Belt and Road Initiative and innovation capabilities of BRI partner countries.
Full size table

Discussion

Our results show that the BRI can facilitate innovative cooperation among countries participating in the BRI. China, as the BRI initiator, will give more innovation cooperation opportunities to BRI partner countries. Under the call of the government, Chinese enterprises have deeply cooperated with BRI partner countries’ enterprises, accelerating technology transfer and knowledge spillover. This is also a significant reason why the BRI significantly increased the proportion of cooperative patents to China’s total patents. We further analyze how the BRI affected innovation cooperation among countries. The BRI weakened the institutional barriers between countries and achieved policy interoperability through the signing of bilateral or multilateral agreements. Moreover, the exchange of talent has increased, and the cultural distance has shortened through cultural exchanges, academic exchanges, etc. All these factors have played a significant role in promoting innovation cooperation among them. For countries participating in the BRI, the total number of international innovation patents, the number of scientific and technical journal papers, and the ratio of R&D expenditure to GDP all increased to varying degrees after joining the BRI. This shows that the BRI improved partner countries’ innovation foundations and capabilities. In general, the BRI can bring about a significant boost to the innovation level of China and partner countries.

However, BRI initiators will face many challenges and constraints in innovative cooperation. Some scholars have argued that the BRI may exacerbate income inequality in partner countries (Bruni, 2019), induce corruption (Kelly et al., 2016), and arouse the resentment of citizens. Meanwhile, it would also bring more troubles to Chinese companies’ overseas investments (Jin et al., 2021). In fact, there are indeed many risks in the advancement of the BRI. First, political risk has always been the key to affecting the BRI. Countries along the Belt and Road have different political systems. It is difficult to achieve complete political communication and trust. Moreover, some of them have serious internal political dissent. China’s foreign policy is difficult to maintain stably and continuously. This would bring great risks and challenges to the overseas investment and innovation cooperation of BRI partner countries. Second, it is difficult to coordinate the interests of countries along the Belt and Road, and the economic risks are relatively high. Many major countries in the world have corresponding diplomatic plans in the areas along the Belt and Road. These diplomatic plans and China’s BRI may diverge, so it is necessary to properly handle the issues of strategic balance and interest coordination. Moreover, innovation cooperation projects generally need large capital investments with long cycles and are easily affected by economic fluctuations. Finally, the economic foundations of the countries along the Belt and Road are quite different, and some innovative cooperation projects do not have high economic benefits. Some countries’ economic foundations are very weak. Before innovative cooperation, they need to be aided in the construction of infrastructure, which will increase the cost of innovative cooperation. For countries with higher levels of innovation, cooperation with countries with low levels of innovation has difficulty achieving the expected results, and the benefits obtained are also relatively small. This will make domestic enterprises and scientific research institutions less motivated in innovation cooperation.

Although we have fully discussed how the BRI affects innovation cooperation among countries from both theoretical and empirical perspectives, there are still some deficiencies and areas that can be expanded. First, we use the number of patents coinvented between countries to measure their innovation cooperation, but there are many types of innovation cooperation, such as jointly establishing R&D institutions and R&D funds and jointly publishing academic papers. Therefore, we can further analyze the heterogeneous impact of the BRI on different types of innovation cooperation and different types of patents in the future. Second, due to data limitations, we use 80 countries and regions around the world as research samples, ignoring the impact of the BRI on other countries in the world. If obtaining data, we can then conduct a worldwide full-sample analysis.

Conclusions and policy implications

Conclusions

Examining the economic and social effects of the BRI from the perspective of international innovation cooperation is of important theoretical value and practical significance. In this paper, 80 countries and regions during the period from 2008 to 2018 are selected to conduct a theoretical analysis and empirical tests on whether the BRI can promote innovation cooperation between China and BRI partner countries. The main research conclusions are as follows:

First, the BRI promoted innovative cooperation among countries to a certain extent. The BRI significantly increased the proportion of cooperative patents to China’s total patents but did not increase the proportion of cooperative patents to the partner countries’ total patents. Additionally, the effect of the BRI is more obvious in promoting innovative cooperation between China and countries with a higher economic development level.

Second, we explore the specific mechanisms by which the BRI affected innovation cooperation. The BRI shortened the institutional distance between countries, providing a better institutional environment and cooperation platform for innovative cooperation. Moreover, it strengthened the exchange of scientific and technological talent, laying a talent foundation for innovative cooperation. Finally, it also inspired the promotion effect of cultural differences on innovation.

Third, for BRI partner countries, the BRI improved their innovation foundation and capabilities. Specifically, their number of international innovation patents, the number of scientific and technical journal papers, and the ratio of R&D expenditure to GDP all increased significantly compared with those before joining the BRI.

Policy implications

This research has important implications for advancing the construction of the BRI and deepening trust and cooperation between countries:

First, various innovation entities should take full advantage of the development opportunities brought about by the BRI and actively respond to policy guidance and calls to strengthen innovation cooperation and improve their own scientific and technological innovation capabilities. Innovation cooperation is an important measure to enhance a country’s innovation strength in the context of globalization. Enterprises, universities, scientific research institutions and other innovation entities should actively grasp the policy dividends to strengthen talent exchanges and innovation cooperation with other countries and continue to acquire new external knowledge and advanced experience to improve the abilities of independent innovation.

Second, China and the BRI partner countries should maintain close communication and adjust and improve the interconnection blueprint in a timely manner. The ultimate goal of the BRI is win‒win cooperation. When major changes occur, China and the BRI partner countries should communicate in a timely manner, fully trust, and adjust corresponding development plans and strategies in time to truly achieve mutual benefits and win‒win results. Additionally, in the face of some countries or organizations’ misunderstandings about the BRI, China and partner countries should continue to advance the blueprint for interconnection based on the basic principles of achieving shared growth through discussion, contribution and collaboration and take concrete actions and cooperation results to provide clarification.

Finally, China should avoid possible risks in the construction of the BRI and establish long-term cooperation mechanisms with other countries. To date, the number of countries or regions that have signed BRI cooperation documents with China has reached 144, covering Asia, Europe, North America, Oceania, Africa, and other global regions. Some are developed countries, and some are developing countries. There are major differences in political systems, customs, cultures, and ideologies among countries. Some frictions and risks inevitably occur in the construction of the BRI. China and relevant countries should further strengthen mutual trust and pragmatic cooperation to establish a long-term cooperation framework.