Major Trends in Public Sector Innovation: A Bibliometric Analysis

It is well known that innovation plays a substantial role in the public sector. However, there are concerns about how far public sector innovation (PSI) research has contributed in providing ideas to the government in formulating and implementing public policy. This study intends to investigate how PSI research has progressed and been disseminated, explore major topics mentioned in PSI studies and determine the primary players in PSI studies. This research analysed the bibliometrics of scholarly publications on public sector innovation as of August 2021, as documented in the Scopus database. We analysed the evolution of PSI research in 53 years by assessing published studies, source titles, types of sources and documents, as well as the languages in which the papers have been published. We additionally analysed PSI’s main research topics by examining popular subject categories, the most often used keywords and title analysis. Finally, we investigated the key actors in PSI research by focusing at the biggest contributions nations to PSI studies, the major establishments involved, as well as authorship and citation analysis. The conclusions suggested that during the initial stages of PSI development half a century ago, public sector innovation attracted the interest of Eastern and Western scholars, as well as the number of books and articles published each year which have increased dramatically. Although there has good inter-country cooperation exists, a deficit in PSI research also exists from specific nations compared to the rest of the globe. Our results contribute significantly to public sector innovation inclusiveness.


INTRODUCTION
Innovation has become prevalent in the current era.The public sector organization's vision, purpose and objective statements increasingly include the "innovation" terms.Scholars and practitioners alike have shown a growing interest in public sector innovation (Osborne & Brown 2011a).Many people believe that innovation may boost the quality of services provided by the government and the capacity of government institutions to address problems in the face of social difficulties.(Damanpour & Schneider 2009) and develop novel ways to meet citizen demands for efficient service delivery (Pärna & von Tunzelmann 2007).
Several studies have looked into trends in public sector innovation (PSI) research.De Vries, Bekkers, and Tummers (2016) presented a comprehensive systematic review of public sector innovation.They looked at the period from 1990 to 2014 and then investigated 181 articles and books on public sector innovation and categorized themes based on the definition of innovation, innovation types, goals of innovation, antecedents of innovation and outcomes of innovation.Potts and Kastelle (2010) introduced an analytic context of PSI investigations, as well as a summary of the 9 papers and sought to develop a new research agenda in public sector innovation research from the fiscal perspective of public sector motivations to innovate.
Bibliometric analysis is a quantitative analysis approach used to identify the current status and emerging trends in a variety of domains.This paper presents a bibliometric analysis of public sector innovation by investigating three key research issues: (a) how public sector innovation research has expanded and been dispersed, (b) What important areas of public sector innovation research have been discussed, and (c) identity of the main parties in PSI research and the way that they have done joint-research.The rest of our research discusses the research methodologies, findings and interpretation and the various considerations and issues involved in responding to the following aspects of the public sector innovation literature.The bibliometric analysis that was conducted had the objective of answering the 3 questions by taking into consideration the following parameters: PSI research's development and dissemination: 1. Quantity of published studies per year; 2. Document types and their sources; and 3. Language used in the documents PSI's main research areas: 1. Field of study; 2. Keyword's frequency; and 3. Title analysis.

Collaborations between key figures and researchers:
1. Nations with highest contributions; 2. Main institutes of higher learning; 3. Authorship analysis; and 4. Citation analysis.
Our study's objective is to gain a deeper insight into the public sector innovation phenomena, particularly its global reach and collaborative efforts.In addition, the most recent data were analysed researchers in making future research recommendations.

METHODOLOGY
This study's technique is based on the manner by which data is collected and filtered, and takes into consideration all the steps required until the final data compilation is solid and suitable for analysis.Therefore, it is necessary to identify the study's topic and breadth before proceeding.We aim to focus on all papers linked to public sector innovation that are currently available in the Scopus database to fulfil the purpose of this study.Due to its repute as the "largest single abstract and indexing database ever built and the largest searchable citation and abstract literature search list (Ahmi & Mohamad 2019) the Scopus database was chosen..
The materials acquired for this study were chosen after taking into consideration recommendations of the research protocol.as per Figure 1.The statistics taken from the Scopus database were obtained and current up to 1 August 2021.Given the limited research on innovation bibliometrics, we limited the papers connected to the public sector based on the document's title and used string search strategy.To achieve this objective, a synonym to the word public sector was searched, and then the following query was done; TITLE(("public administrat*" OR "public organization*" OR government* OR "public service" OR "public sphere" OR "public sector") AND innovation).A total of 1643 documents were returned from this query.A series of data cleanings revealed that the papers were not duplicated.; as a result, a similar number of papers were kept following the procedure.The Scopus database was used to compile all of the information which were then exported into search information systems (.ris) and commaseparated values (.csv) formatted files.(Moher et al. 2009) This study used the bibliometric technique to examine all of the public sector innovation research trends.The database contains information on publications such as year published, type of documents, published language, area of topic, source title, keywords, abstract, country, affiliation, citations and authorship.To analyse and visualize the data, we have utilised Microsoft Excel, Harzing's Publish or Perish and VOSviewer tools.In our study, we used the VOSviewer software for the constructing and visualising of the bibliometric networks (Perianes-Rodriguez, Waltman, and van Eck 2016).VOSviewer graphically represents the nodal network using two uniform weights, which indicate the number and the connections' overall strength.VOSviewer's network size and interconnecting interlinking lines, which Leiden University established, represent the significance and strength of the connections.The procedures shown in Figure 2 can be used to accomplish the intended outcomes of doing the bibliometric analysis provided in this technique.

RESULTS AND ANALYSIS OF FINDINGS
This paper's analysis incorporated the following elements of scholarly works to address the research questions outlined in the previous sections: year of publication, document category, publishing by source title, kind of source, country, and institution, document languages, subject areas, citation patterns and themes in public sector innovation according to the keywords & title, in addition to the abstract and authorship.Some of the research have been further developed by establishing the number of cited publications frequency and percentage (NCP), total citations (TC), average citation per publication (C/P), average citation per cited publication (C/CP), g-index and h-index.The publisher's name is reported for the most prolific source title with the current Cite Score, Scimago Journal Rank (SJR) 2020 and Source Normalized Impact per Paper (SNIP) 2020 as per the Scopus database.SJR measures the weighted citations obtained by the source title.In contrast, SNIP estimates the number of legitimate citations received compared to the citations anticipated in the topic area of the originating title.The citation analysis was published as citation metrics and 30 of the most often referenced articles in public sector innovation were made public.

CURRENT STATE OF PUBLICATION IN PUBLIC SECTOR INNOVATION
In order to respond to the first research question, (What is the current state of public sector innovation?),We looked into the publication trend in public sector innovation based on total publications by year, type of document, publication by source title, publication by nation, publication by institution, language and publishing topic area.The Scopus database was used to acquire bibliographic data which was then used in the study to calculate the data.

PUBLICATION BY YEAR
The detailed statistics of annual publications on public sector innovation are shown in Table 1.According to the Scopus database, 108 papers were published in 2018, with an increase to 124 publications in 2019, followed by an increase to 169 publications in 2020, and a slight decrease to 103 papers in the final 4 months of 2020.The publication trend, as shown in Figure 3, is indicating the imminent tremendous rise of PSI research.The five earliest papers written by Thompson (1968) discussed scientific management and innovation; Boaden (1971) discussed innovation and change; Ashford and Heaton (1975) on the effect of innovation on government activity; Pavitt and Walker (1976) on government policies towards innovation; and (Staats 1976) discussed innovation climate.The topics discussed in those five publications still captivates our attention to this day.

SOURCES TYPES
In addition, the goal of this research was to find out where public sector innovation related.Table 2 reveals that the most widely used source was journals, accounting for 1,097 of the total (66.77%), after that, it was followed by conference proceedings (n = 269, 16.37, a huge difference in materials had already been made public by analysing the data depending on the source document type when compared to journals.The least common document was trade journals (n = 14, 0.85%), which were generally meant for a certain industry, trade, or kind of company, which excluded one undefined source.They are generally published in a magazine periodically with a topical subject.The data were also used to analyse the document types.Scopus indexes serial publications' main document types, which indicates that the researcher is also the author responsible for the reported results.Types of secondary documents, such as book reviews, in which the author is not the researcher, are not listed in the Scopus database.As a result of this analysis, we were able to determine the number of research by researchers on public sector innovation and the number of publications produced by these academics.

CATEGORY OF DOCUMENT
Category of document type pertains to the published documents and how it is categorised into a few groups: conference paper, book chapter, article, editorial, review, review and note.Table 3 sums up the dispersion of published documents on public sector innovation which fall within 11 document types.As illustrated in Table 3, a majority of the total number of publications originated from articles by researchers (n = 1025, 62.39%).This was followed by conference papers (n = 309, 18.81%).Book chapters represented 10.04% (n = 165) of the publication on public sector innovation.The remaining document types, such as editorials, books, reviews, notes, short surveys, letters, conference reviews and erratum, accounted for fewer than 4% of the overall number of publications.

KEY AREAS OF PUBLIC SECTOR INNOVATION RESEARCH
The most important aspects of PSI research were examined in the context of (a) principal topic areas, (b) keywords frequency, and (c) titles of document.

PRINCIPAL TOPIC AREAS
As illustrated in Table 6, this study categorised the documents according to their subject area.The data indicated that PSI research had been conducted in a range of subject areas.However, most PSI studies were in the field of social sciences (42.12%) and business, management

KEYWORD ANALYSIS
Figure 4 depicts a network representation of the author's keywords, each of which had at least ten occurrences.This research employed VOSviewer, a computer programme for creating and visualising authors' keywords which are then mapped using bibliometric networks.Relationships with other keywords are shown by the colour, the diameter of the circle, size of the font and the thickness of the connecting lines.Keywords that had the same colour were frequently grouped.In our study, innovation, government, innovation policy, government subsidies, innovation performance, green innovation, innovation system, China and triple helix have similar colours, implying that these keywords were inextricably linked and frequently cooccurred (Sweileh et al. 2017).
The following table summarises the most often mentioned terms in research on public sector innovation.After omitting the search query's core keywords, the data revealed that "innovation" was the keyword most closely associated with public sector innovation (n = 489, 29.76%).The keyword "public sector" and "government" were used interchangeably in the documents and present 9.74% (public sector) and 6.27% (government) of the total documents.Other terms that appeared more than 50 times including:

TITLE ANALYSIS
Figure 5 depicts a network of word co-occurrences according to the title fields with at least ten instances of a word.We applied a binary counting technique in which the frequency with which a noun phrase appears in the title of a publication is irrelevant.A noun phrase that appears just once in the title of a publication is regarded in the same way as a noun phrase that appears 10 times, according to Perianes-Rodriguez, Waltman, and van Eck (2016).Figure 5 shows that the keyword "innovation" was the dominant term in PSI study, functioning as the core node of the entire network.The relative relevance of occurrence words is represented by the size of the nodes and the intensity of the link between the words is shown by the thickness of the connecting lines.As shown by the same hue, related terms were frequently reported together.The illustrated diagram, for example, suggests that (a) innovation, (b) government, (c) public administration, (d) public service, (e) local government, (f) social innovation, (g) innovation policy, (h) application, and (i) business (all coloured green) are strongly linked and frequently occur simultaneously.
VOSviewer produced eight distinct colours from the titles of the articles in our investigation, indicating five clusters with 44 terms that are closely related and appear frequently together.

COLLABORATION AND MAJOR PLAYERS IN PUBLIC SECTOR INNOVATION STUDIES
The features of scientific partnerships on PSI research were examined in this study, which included(a) the nations that produced the most often, (b) the major institutions involved in PSI research, (c) authorship analysis, and (d) citation analysis.Table 8 shows the top 30 nations where the majority of public sector innovation research is conducted.The United States was the premier country with 286 publications, covering 17.41% of the world's total publication on public sector innovation.While China and United Kingdom contributed 262 publications (15.95%) and 204 publications (14.42%) each to the world total publications.The remaining writers' country connections accounted for less than 10% of the total and were dispersed around the world-Australia, Netherlands, Denmark, Italy, Germany, South Korea, Canada, Spain, Norway, Brazil, Finland, Malaysia, Sweden, France, Singapore, Russian, Taiwan, Hong Kong, Indonesia, India South Africa, Belgium, Japan, Switzerland, Greece, Ireland and Mexico.Clearly, public sector innovation plays an essential function in a variety of geographically diverse places.

MAIN INSTITUTION
Table 9 lists the institutions where the majority of the articles on the public sector's innovation were produced.

AUTHORSHIP ANALYSIS
The following table summarises the number of authors for each document.547 (33.29 %) of the 1,643 publications included in this study were single-authored, while the rest had multiple authors.
Almost 497 papers (30.24%) had two writers who collaborated on the paper, whereas three authors coauthored 324 documents (19.72%).There was one document with more than 22 co-authors.The authors listed in Table 11 were the most productive in terms of their contributions to public sector innovation research.Demircioglu had the most publications on public sector innovation, with 11 publications affiliated with the National University of Singapore.The second most productive author publishing on public sector innovation was Niehave (10 publications) from Universität Siegen, Information Systems, Germany.The third most productive author was Osborne (9 publications) from the University of Edinburgh Business School, Edinburgh, United Kingdom.Finally, with ten publications each respectively, Bekkers, affiliated with Erasmus Universiteit Rotterdam, Department of Public Administration and Sociology, Rotterdam, Netherlands and Etzkowitz affiliated with International Triple Helix Institute Palo Alto VA, International Triple Helix Institute, Palo Alto, United States were the fourth and fifth placed authors who had the most publications on public sector innovation.

CITATION ANALYSIS
Table 12 shows the citation metrics of the papers gathered from the Scopus database.There were 27,550 citations reported in 53 years (1968 -2021) for 1,643 articles, with an average of 519.81 citation every year.Table 13 summarizes the 30 documents on public sector innovation, depending on how many times each was mentioned, it was found that the documents most often cited was "The dynamics of innovation: From National Systems and "mode 2" to a Triple Helix of universityindustry-government relations" by author Etzkowitz and Leydesdorff (2000).Other document most often cited were related to e-government by Carter and Bélanger (2005), innovation collaboration by Wallsten (2000); Sørensen and Torfing (2011) and Damanpour and Schneider (2009).The citation mapping for documents having at least 30 citations is shown in Figure 8.It depicts the most influential writers in the field and how their thoughts intertwined.Figure 9 shows the countries of origin in further detail.Moreover, the analysis successfully indicated a modification in the level of involvement of developing countries in PSI studies.PSI research was dominated by the United States, China and the United Kingdom.This study demonstrated that research outputs from developing countries are gaining momentum, increasing the number of varied scholars conducting PSI research.According to the data in the preceding sections' tables and figures, the public sector's trend toward innovation seems to be the one that many will embrace in the future.This tendency is expected to expand as raising the attention to improving the productivity of public service delivery, service digitization and public sector agency performance increases.In addition, the present Covid 19 pandemic has compelled the public sector to think and act innovatively when formulating and executing policies.
In response to the third objective, our analysis of areas of study, keywords, and titles revealed that PSI research primarily focused on domain innovation.According to the data, social sciences are the most frequent subject area in PSI research.The most frequently encountered theme in PSI research is 'innovation'.The key points of this field can be observed in the results of VOSviewer's keyword, title and summary analyses.For instance, while reviewing Table 7, we discovered that, in contrast to synonyms for the public sector, "government data processing," "e-government," "open innovation," and "innovation performance" were among the most often used phrases in the collected documents.
Regarding the third research question, which were concerned with the major players in PSI research and their collaborative efforts.Our research looked at countries, institutions, authors and citations, and there seems to be a good scientific collaboration on PSI research globally.The United States, China, and the United Kingdom ranked first through third in scholarly articles on public sector innovation.The United States had the most papers on PSI research, indicating that it was a pioneer in the global and may have focused funding into it.This is reinforced further by the fact that the United States boasts of the world's largest concentration of top-ranked universities.The significant disparity between PSI research conducted in these countries and the rest of the globe should be a cause for concern, as one of the primary purposes of public sector innovation is to improve public sector delivery services.The relevance of PSI publications can be explained through the explanation of citation metrics in this research.One thousand six hundred forty-three articles and over 27,550 citations have been published due to 53 years of publications in the PSI field (1968 -2021).In aggregate, PSI research documents retrieved from the Scopus database are mentioned 519.81 times every year, averaging 16.77 citations per paper and 2.25 authors per paper.

LIMITATIONS AND FUTURE RESEARCH
The objective of this research was to comprehensively review the publications related to public sector innovation research from 1968 to 2021 using bibliometric analysis.Evolutionary mapping of public sector innovation, key topic areas and collaborations across various categories are the number of published studies per year, sources, languages, subject areas, keywords, document titles, contributing countries, main institutions, authorship, etc. citation.The findings indicated that Eastern and Western scholars conducted the early researches on PSI.However, it should be noted that no search query is 100% ideal; hence, false positive and negative results are to be expected (Sweileh et al. 2017).The current analysis relies entirely on the Scopus database for document retrieval.Even though Scopus is one of the most comprehensive databases for academic research preservation., it cannot possibly include all published sources (Sweileh et al. 2017;Ahmi & Mohamad 2019).Additional databases, such as Web of Science, Google Scholar, Dimensions and others, may be utilised in future research.Integrating all of these databases can contribute to the creation of innovative and valuable results.Despite these limitations, the current study contributes to knowledge by highlighting recent research trends in the public sector.Additionally, this research contributes by utilising the bibliometric method to enhance public sector innovation knowledge.
The research's objective is to demonstrate that most academic studies employed the title as a catchphrase, the authors as key references, and the institutions as the focal point of information.Subsequently, some researchers may concentrate on search terms contained in the abstract or keyword field.Additional research is required to investigate and assist in bridging the gap that may exist in the context of public sector innovation development.While this analysis focuses on innovation in the public sector, future research may examine innovation development within businesses, non-governmental organisations, and small and medium-sized enterprises (SMEs).

FIGURE 1 .
FIGURE 1. Flow diagram of the search strategy(Moher et al. 2009)

FIGURE 2 .
FIGURE 2. Stages of the bibliometric analysis procedures (a) e-government; (b) local government; (c) public policy; (d) government data processing; (e) China; (f) public administration; (g) public services; (h) open innovation; (i) public sector innovation; and (j) technological innovation.The majority of these keywords were grouped around public sector innovation.

FIGURE 5 .
FIGURE 5. VOSviewer visualization of a term co-occurrence network based on title fields (binary counting).

Figure 6
Figure 6 illustrates 10 of the world's most productive countries, leading to the growth of PSI research activities.The United States, China, and the United Kingdom all contribute significantly to the advancement of PSI research.

FIGURE 6 .
FIGURE 6. Top 10 most productive countries in PSI research Out of the 1,643 documents, National University of Singapore (n = 24), which ranked consistently among the most prestigious institutions in the world, provided the highest number of articles on public sector innovation.Other institutions which also had high number of contributions were (a) Roskilde Universitet (n = 20); (b) The University of Manchester (n = 18); (c) Delft University of Technology (n = 14); (d) Erasmus Universiteit Rotterdam (n = 14); (e) Xi'an Jiatong University (n = 13); and Tsinghua University (n = 13).

FIGURE 8 .
FIGURE 8. Network visualisation map of the citation of public sector innovation documents.

TABLE 1
Notes: TP=total number of publications; NCP=number of cited publications; TC=total citations; C/P=average citations per publication; C/CP=average citations per cited publication; h=h-index; and g=g-index.... cont.FIGURE 3. Publication and citation trend in public sector innovation research

TABLE 2 .
Sources for public sector innovation research

TABLE 3 .
Public sector innovation document type

Table 4
summarised the most active source titles with a minimum of ten publications.Research Policy contributed the highest number of publications on public sector innovation (n = 40).Research Policy is widely regarded as the leading journal in innovation studies, with a remarkably high 'Impact Factor' for a multidisciplinary social science journal.This was followed by the Public Management Review (PMR) (n = 30).PMR is a wellknown journal that has evolved alongside the evolution of public management and provides a forum for healthy discourse on public management-related issues.ACM International Conference Proceeding Series contributed a third of the publications on public sector innovation (n = 28).ACM Publications is the preeminent platform for presenting cutting-edge research and ground-breaking findings, pragmatic options to real-world problems, technological news, and opinions from the world's leading thinkers in computing.

TABLE 4 .
Most Active Source TitleRussian, Deutsch, Italian, Japanese, Dutch, Finnish, Norwegian, Hungarian, Lithuanian, Moldavian, Moldovan, Polish, Romanian and Ukrainian, however these made up less than 1% of the total documents respectively.Although there were articles on public sector innovation that were published in languages other than English, they represented a small proportion of the total.
DOCUMENTATION LANGUAGESTable 5 indicated that English was the most often utilised language, accounting for 94.77% of the 1,643 publications on PSI research.The second most popular language was Spanish, which accounted for only 1.20% of total publications.The remaining publications were written in 17 other languages, namely Chinese, Portuguese, French,

TABLE 5 .
Languages used for public sector innovation research publications

TABLE 8 .
Geographic origin of public sector innovation research

TABLE 9 .
Most influential institutions with minimum of ten publications on public sector innovation Notes: TP=total number of publications; NCP=number of cited publications; TC=total citations; C/P=average citations per publication; C/CP=average citations per cited publication; h=h-index; and g=g-index.

TABLE 10 .
Number of author(s) per document *Conference review document.No author is listed.

TABLE 11 .
Most Productive Authors

TABLE 12 .
Public sector innovation research citations metrics