A Scientometric Analysis of University Business Incubators and Accelerators Based on 20 Year of Research

University business incubators (UBIs) are established with a vision to promote entrepreneurship at university levels by providing people with support services. The purpose of this approach is to stimulate the growth and development of new startups, spin-offs, TTOs (Technology transfer offices), and existing firms. (UBIs) are dedicating a facility by providing subsidized office space, consultation, and other services. The current study is aimed to systematically review the literature of university business incubators and accelerators by keeping in view the importance of (UBIs). Besides, it also focuses on their roles of performance in economic and social development by promoting entrepreneurship at university campuses. This study is unique in a sense that it contributes to the university business incubation research by reviewing, synthesizing, and evaluating its literature with ‘citations-based analysis approach’. Data of this research has been analyzed with the ‘Scopus Database’ since, 2001 to 2020. Articles have been screened and shortlisted based on predefined eligibility criteria. We have used ‘R-Studio Biblioshiny Software’ for articles’ Scientometric analysis including most influential journals, authors, articles, and top contributing countries. Quantitative analysis has performed including yearly publications trend, citations trend, and top articles based on average citations. VOS-Viewer Software has also been used to perform co-occurrence analysis and co-authorship analysis. The content analysis of top 50, highly cited articles has been conducted to identify the methodological approaches, variables, and theoretical underpinnings. Findings contribute to university business incubation’s (UBIs), literature by analyzing the articles individually, start-ups, incubators, networks, and university levels. Theoretical underpinnings used in (UBIs), represent the ‘institutional theory’, ‘knowledge spillover theory of entrepreneurship’, ‘resource-based view’ (RBV), ‘structural theory’, and ‘triple helix model’.


Introduction
Entrepreneurship has always been perceived as creating, launching, and operating new start-ups from a small scale at conventional level. However, this notion of entrepreneurship has been changed now due to its main role and performance in the economic growth and development. Moreover, it is reducing unemployment, exploiting opportunities, and providing a wide range of products and services, that benefits the society as a whole (Al-edenat, 2021).The creation and development of new startups, and firms significantly contribute to the global economy by promoting the social and economic development in the society (Zapata- Guerrero et al., 2021). While from last few decades, there has been an exponential growth in entrepreneurship development initiatives, which promotes entrepreneurship education and development programs at university campuses. Furthermore, it introduces special zones in the form of student's start-up centers, business incubators, and accelerators (McGee et al., 2021).
Moreover, business incubators have been considered as enablers and launching centers for the new startups, which tackle unemployment, economic development, and generate wealth in several developed countries (Al-edenat, 2021). Furthermore, business incubators, and accelerators have been considered as important tools and supportive mechanisms across the world. They not only create the new ventures, but also nurture its growth and development (Lukeš et al., 2019;Nicholls-Nixon & Valliere, 2020). Similarly, business incubators and start up centers are established to create, nurture, develop, and accelerate the technologybased firms. They are also contributing as important tools to introduce, initiate and revive the innovation in products and services, which paves a way to commercialize the current research from the university campuses (Aaboen, 2009).
Business incubators or accelerators are established to provide conducive environment to the startups so that they can perceive, initiate, nurture, and develop their business ideas and turn them into viable business ventures. In this way, business incubators have emerged as significant strategic tools to promote economic development in the industrialized and emerging economies, worldwide (Kiran & Bose, 2020). Business incubators provide support and services to newly established small businesses, such as office working space, consultation regarding legal aspects, guidance, trainings and workshops, and capital support. They also support the customized business services as per the needs and requirements of the startups (Del Campo et al.,2020). In this way, business incubators boost small business development and help them to cope with the growth challenges (Li et al., 2020).
Business incubation and entrepreneurship development centers are classified into three further categories that are (a) publicly funded business incubation, innovation, and technology transfer offices (TTOs), (b) university business Journal of Management and Research Volume 9 Issue 1, June 2022 incubators and accelerators, (c) corporate private incubators. All these business centers have a common goal to promote entrepreneurial initiatives. They also support small businesses and create a hub of business activity (Piterou & Birch, 2016). However, among all these types of incubation centers, university business incubators (UBIs), are considered as an integral part of the entrepreneurship ecosystem.
Besides, they also promote and support entrepreneurial activities at university campuses (Nicholls-Nixon et al., 2021). Although , the University incubators have gained maximum importance in entrepreneurial eco-system due to their distinctive performance in the way of success and development of university startups (Maritz et al., 2021). Hence, universities have made huge investments in the establishment of incubation centers and entrepreneurship development programs, over the last two decades across the globe (Breznitz & Zhang, 2019;Metcalf et al., 2021). University incubation centers are also influencing the startups in the reginal development along with promoting the entrepreneurial eco-system in the universities (Franco, 2020). Pellegrini and Johnson-Sheehan (2021), find that most states are supporting their public sector universities to develop their new products and services by launching new startups and establishing entrepreneurial ecosystems, only in USA. One of the initiatives to promote entrepreneurship in this eco-system is to establish university business incubators (UBIs), which help in the launch of start-ups by students, researchers, university professors, and local entrepreneurs. Moreover, (UBIs), are established with a vision to foster transnational entrepreneurship (Pellegrini & Johnson-Sheehan, 2021), by providing support service. They are also assisting the growth and development of new startups, spin-offs, and existing firms through a dedicated facility, which provide subsidized office space, consultation, and other services (Etzkowitz, 2002;Grimaldi & Grandi, 2005).
The current study is aimed to systematically review the literature on (UBIs), and accelerators by keeping in view their importance and role in economic and social development by promoting entrepreneurship at university campuses. Although, prior studies have been conducted on the business incubators but there is a dearth of systematic literature on the (UBIs), u and accelerators. So, this particular study is contributing to the (UBIs), literature by reviewing, synthesizing, evaluating it with citations-based analysis in its unique ways. This research has twofold objectives a) to perform Scientometric analysis of bibliographic data, retrieved from Scopus data base, and b) to perform the content analysis of top 50 highly cited articles on (UBIs).
Dr Hasan Murad School of Management Volume 9 Issue 1, June 2022

Methodology
This citation-based systematic literature review about (UBIs), and accelerators was conducted with a very articulate and rigorous process. Moreover, it was processed to ensure maximum objectivity in the articles search criteria and final selection based on predefined eligibility parameters. We performed search on Scopus database by applying below mentioned search criteria: After performing the query on Scopus advanced search with the articles search criteria, there were 432 articles, appeared in the initial results. Bibliographic data of these articles were exported in CSV and Bibtex format. After applying stringent eligibility criteria, 268 out of 432 articles, were included in this systematic. We read the articles' titles, abstracts, and keywords to select those articles which meet eligibility criteria. The selected articles were as follows; a) if any of these keyword(s) (university incubator(s), university accelerator(s), university business incubator, university business accelerator, university incubation, and academic incubator) are found in title, abstract or keywords; b) if the issue of research was related to any aspect of (UBIs), whether directly or indirectly (indirectly through stakeholders). We excluded all those articles which were not related to research on (UBIs). Although, the current research was conducted on the various aspects of business incubators, we still focused on the various facets of (UBIs). However, the objectives of this citation-based systematic literature review was another focus of this particular study. We used R-Studio Biblioshiny package developed by Aria and Cuccurullo, (2017), Scientometric analysis that included most influential journals, authors, articles, and top contributing countries.
Microsoft excel software was used for quantitative analysis of the yearly publications trend, citations trend, and top articles based on average citations. NVivo (R-1) software was used to identify most frequent words in the articles, titles, abstracts and key words. Similarly, VOS-Viewer software was used to perform co-occurrence analysis of key words based on the bibliometrics, cooccurrences, and content of the articles. For this purpose, the following mentioned citations were based on SLR, in which we reviewed the work of (Ahmad et al., 2020;Almeida & de Paula, 2019;Corbet et al., 2019;Pourkhani et al., 2019), and adopted various technical analysis techniques from these articles.

Analysis and Results
The results are divided into three main sections. Section 1, represents annual publications trend, annual citations trend, influential journals, influential authors, influential papers, and influential countries in the field of university business incubation. Section 2, represents co-occurrence analysis of article's titles, abstracts, keywords, and co-authorship analysis. Section 3, represents content analysis of top 50 journals.
*Annual growth rate 31.8%   Table 3 represents top influential journals, in which Ranks 1, indicates the 'journals' according to total citations and Rank 2, indicates the 'ranking of

Ranking of Top 10 Countries Based on Publications
Top ten countries producing research publications in the area of university business incubation are USA, UK, Spain, Sweden, Italy, Brazil, Netherlands,   Table 4 ranks the top 25 most influential authors, based on the total citations of their articles in the field of business incubation.  Have you been served?

Section 2 Co-occurrence and Co-Authorship Analysis
Co-occurrence and Co-authorship Analysis was conducted by using VOS Viewer software, which was developed by van Eck and Waltman (2010). This analysis indicates the terms co-occurrence pattern across different clusters. Figure: 5 represents the co-occurrence based on titles and abstracts of the articles, minimum occurrence of a term was kept at 10. Which means, any term having frequency of less than 10 was not included in the analysis, so 163 terms met threshold and 7 clusters were developed. Figure 6 depicts the co-occurrence based on articles' titles, minimum occurrence of a term was kept at 2 so 122 terms met threshold12 clusters were developed. Further, Figure 7 also represents cooccurrence based on the abstracts, whereas minimum occurrence of a term was kept at 10 and 148 terms, met threshold 6 major clusters were emerged. Figure 8 represents co-occurrence based on keywords in which minimum occurrence of a keyword was kept at 2 and 125 terms met threshold and 11 clusters were emerged. Lastly, Figure: 9 represents co-authorship based analysis whereas minimum articles of an author were kept at 1 and found that 32 authors were connected and 7 clusters were emerged.

Figure 6
Co-occurrence Based on Article Titles

Figure 7
Co-occurrence Based on Articles Abstracts

Figure 8
Co-occurrence Based on Articles Keywords  Table 7 represents the frequencies of top 20 keywords of all 268 articles. These are highlighted keywords which further consist of all three common categories, such as Titles, Abstracts, and Keywords. Table: 8 Analysis of the top 50 articles research type indicates that majority 23 (45%), articles were qualitative studies, 13 (25%), articles were quantitative studies, 12 (24%), articles were theoretical and review papers, and 3(6%), articles adopted mixed methods designs.
In qualitative studies, majority of the articles, around 15(65%), adopted case study designs followed by comparative, grounded theory, longitudinal, and narrative. In quantitative studies, majority articles 11(85%), adopted survey research design, followed by longitudinal design. So it could be articulated that majority of the articles were qualitative and theoretical among top 50 highly cited publications. Majority of the articles were out of 50 highly cited articles with adopted qualitative research designs, as 45%, followed by 25% quantitative, and 24% were found to be review articles. In qualitative studies majority 65% followed the case study designs, where in quantitative majority 85% followed survey designs.  Table 9 depicts analysis of quantitative studies. It indicates that the variables which were studied at three levels individually, Start Up/Spin-off/Firms/TTOs and university or incubators level. The focus of the current research at individual level variables were the entrepreneurs' experiences at the incubation. The main focus was their formal education, prior knowledge of customer problems, markets, how do they acquire the knowledge of technology and market, network reliance, innovation radicalness, and surrogate entrepreneur.

Content Analysis of Top 50 Highly Cited Articles
At startup level, this particular research was focused on the understanding characteristics of the Start ups/Spin-offs, their funding sources. It further was focused on how they maintain relationship with university, and the incubators. Moreover, registering patents, making industrial collaborations, geographical location of the incubators, networking support, entrepreneurial support, innovation Dr Hasan Murad School of Management Volume 9 Issue 1, June 2022 strategy, performance (Sales growth, employment growth participation in domestic R&D programs), and employment generation cost. At the university and incubator level, this research was focused on knowledge flows, from university to incubator firms, licensing agreement, incubator performance (Revenues, total funds raised, venture capital funding, failure, and graduation), incentive structures for faculty to engage in commercialization, localcontext support mechanisms, number of academic spin-offs, and innovations (Technological, product, organizational). Directional support and external networks Normative frameworks Table 10 indicates the main study variables of qualitative studies among top 50 highly cited articles. In qualitative studies, at university level, this research was focused on the structures of university, its technology transfers offices, licensing for equity, knowledge source, university links, and support measures for entrepreneurship education programs. Besides, attitudes towards entrepreneurship, suitability of management, entrepreneurial organization and governance structure, support infrastructures for entrepreneurship, entrepreneurship encouragement offerings, and commercialization of research ideas were also the part of focus. Similarly, at incubator level, the focus of major research was on the business model of incubator, value creation processes, networked entity, strategic position of incubators, assessment model, and technology incubator. Further, the clustering effects, provision of physical infrastructure, support infrastructures, and TTO staff's specialist technical skills were also under the consideration. Moreover, research was also focused on reward systems, human, financial, technological, and social capital. At start up level, the research focus was on the opportunity recognition process, value creation in professional service firms, cognitive, organizational, and social proximity, by giving the clustering effect credibility and image access to professional networks, and performativity.
Another stream of research was focused on network dynamics of the incubators, including social/personal networks, trust, directional support and external networks, and normative frameworks of the incubators.

Conclusion
University business incubators (UBIs), play important roles in the development and growth of entrepreneurship at universities by providing conducive and enabling environment, infrastructure, and essential services to the start-ups. The current study is aimed to conduct the systematic review about university business incubators (UBIs), and accelerators. So, this particular study is contributing to the (UBI), literature by reviewing, synthesizing, and evaluating it with the citations-based analysis. This particular study had twofold objectives a) to perform the Scientometric analysis of bibliographic data, retrieved from Scopus data base, and b) to perform the content analysis of top 50 highly cited articles, on university business incubators.
Annual publications trend revealed that annual publications growth rate is 31.8%. Majority of the researches on (UBIs), were carried out in the last decade among (2011 to 2020) years, as there was almost 300% increase in the publications. It clearly indicated the importance of research on (UBIs), for the promotion and development of entrepreneurship at the university campuses. Moreover, annual citations trend indicated that majority articles were being cited and published during the time period of (2001 to 2010). Co-occurrence and Coauthorship Analysis was conducted by using VOS Viewer software which was developed by van Eck and Waltman (2010). Co-occurrence based on titles, abstracts, and keywords analysis indicated the terms of co-occurrence pattern across different clusters. Analysis of the top 50 articles research type indicated that majority 23 (45%) articles were qualitative studies, 13 (25%) articles were quantitative studies, and 12 (24%) articles were theoretical and review papers, and 3(6%) articles adopted the mixed method designs. In qualitative studies, majority 15(65%) adopted the case study designs which were followed by the comparative, grounded theory, longitudinal, and narrative. In quantitative studies, majority 11(85%) adopted the survey research design followed by longitudinal design. So, it could be articulated that majority of the articles were qualitative, and theoretical among the top 50 highly cited publications. Theoretical underpinnings used in (UBIs), were the institutional theory, knowledge spillover theory of entrepreneurship, resource-based view (RBV), structural theory, and triple helix model.

Limitations of The Study
This citation-based SLR was conducted on the Scopus database only and it was limited to 20 years' time period of research from 2001 to 2020. So findings might be understood accordingly, and results might not be generalized to other databases. Researchers tried their best to ensure the maximum objectivity, while screening the eligible articles. The authors declared some possibilities of error or omission, during screening, selection, and analysis of the articles.