Corruption in economics: a bibliometric analysis and research agenda

ABSTRACT We conducted a bibliometric analysis of the literature on corruption in the discipline of economics (4,488 articles) over the past 51 years between 1968–2019. Through this methodology, we identified seven research streams: (1) the economic framework of crime and corruption, (2) the legal institutions and corruption, (3) the effect of corruption on aspects of national economics, (4) the combating and monitoring of corruption, (5) the determinants of corruption, (6) political institutions and corruption, and (7) the effect of corruption on firms. In addition to these research clusters, we also identified the key journals, articles, countries, institutions, authors, data sources, measurements, theoretical frameworks, and networks dealing with this issue. Finally, we suggested 20 future research questions. Video Abstract Read the transcript Watch the video on Vimeo


I. Introduction
Economists traditionally view corruption as a misuse of power for private gain (Shleifer and Vishny 1993;Treisman 2000). Corruption has been blamed for the failure of policy in some developing countries (Treisman 2000) and found to reduce investment, economic growth, and development (Mauro 1995;Bardhan 2017). As a result, academic researchers, controlling bodies (e.g., the IMF, 1 OECD, 2 and World Bank) and nations (e.g., America's FCPA of 1977 3 and the OECD committee on bribery 1989 4 ) started reviewing and analysing the pathology of corruption and crime in the economy and society. Consequently, a substantial but scattered body of literature on corruption in economics has developed. We synthesized 51 years of research (between 1968 and 2019) (see Figure 1) to provide more clarity on the research clusters and research directions in the field.
To explore the literature, we conducted a bibliometric citation analysis of 4,488 articles on corruption in economics (Yuret 2014(Yuret , 2018Rath and Wohlrabe 2015a;Zupic and Čater 2015;Sommer and Wohlrabe 2016;Meyer and Wohlrabe 2017;Bahoo, Alon, and Paltrinieri 2019;Bahoo 2020). Our analysis contributes to the literature by answering the following questions: (1) What are the leading research streams in the literature on corruption in economics?
(2) What are the key journals, articles, countries, institutions, authors, data sources, measurements, theoretical frameworks, and networks in this field?
(3) What are the future research directions?
Using 18 keywords for corruption that included combinations of the words 'economics,' 'economy,' and 'economic,' we searched the ISI Web of Knowledge (WOK) database for articles on the topic. We selected these words using a systematic, three-step process outlined in Table A1. Our first search resulted in 5,671 articles. In the next step, we excluded irrelevant articles by reviewing titles and abstracts. Our final set included 4,488 articles published between 1968 and 2019 dealing with corruption in economics. Figure 1, which illustrates the growth in articles per year on the topic, shows a sharp growth trend beginning in the 1990 s after the Western world passed anti-corruption laws and formed an OECD committee on bribery.

Key journals and networks
Three hundred seventy-two journals published the 4,488 articles in our sample. Using HistCite, we ranked the top 11 journals that had the largest  number of citation references and articles published on the topic (see Table A2). In both rankings, the journals Applied Economics and Applied Economics Letters emerged as the most influential and provided quality research on corruption in economics. Furthermore, using VOSviwer we determined that Applied Economics Letters was also among the topcited journal networks (see Figure 2). Influential countries, institutions, authors, articles, and networks Using these two software programs, we ranked the most influential countries, institutions, authors, and networks in the field (see Table A2). With regard to authors, 6,828 authors wrote the 4,488 articles in our sample. Figure 3 illustrates the top 11 authors and networks among them, which is useful for policymakers and prospective researchers for future projects. With regard to countries and institutions, most studies came from Western countries such as the US and Europe, reflecting the serious desire to overcome the problem of corruption and crime. China is also emerging as a major contributor.
Our sample of 4,488 articles had 10,629 total local citations (TLC) and 97319 total global citations (TGC). We also divided the top 11 trending articles from 1968 to 2019 into two categories based on TLC/t (total local citations per year) and TGC/t (total global citations per year) (see Table A2).

Keyword networks to identify research areas
The keywords assigned by authors or the ISI WOK database to a research article represent the field of study and directions of the literature. Therefore, using VOSviwer we created keyword networks based on the repetition of words, which is called cartography analysis. Figure 4 depicts the resulting networks and identifies the associated research areas. As the figure indicates, the most repeated keywords in the literature are corruption, crime, economy, economic growth, deterrence, punishment, law, institutions, models, determinants, causes, and consequences. On the other hand, the keywords that appeared least frequently are firm performance, firm, earning management, political institutions, politics. The findings from Figure 4 confirm that two critical areas of research-political institutions and corruption, and the effect of corruption on firms-are underdeveloped and neglected. These two areas of research contain knowledge gaps that suggest the need for further investigation.
Citation mapping: identification of research streams, trends, and synthesis We used bibliometric co-citation analysis (Cainelli et al. 2012;Rath and Wohlrabe 2015b;Aria and Cuccurullo 2017;Paltrinieri et al. 2019) and content analysis (Bahoo et al. 2018;Gaur and Kumar 2018) to identify the research streams in the literature on corruption in economics. In the first step, bibliometrics co-citation analysis identified the 70 top-cited papers, resulting in the citation map depicted in Figure 5. Second, we applied traditional content analysis to these 70 articles to understand the content . This quantitative and qualitative process resulted in the following seven research streams in the literature: (1) the economic framework of crime and corruption, (2) the legal institutions and corruption, (3) the effect of corruption on aspects of national economics, (4) the combating and monitoring of corruption, (5) the determinants of corruption, (6) political institutions and corruption,  Table A3.
These seven research streams are interconnected. The key frameworks of corruption and crime (Becker 1968;Rose-Ackerman 1975;Olken 2009) are helpful in explaining the effect of corruption on the economy (Macrae 1982;Mauro 1995;Fisman and Svensson 2007), businesses and firms (Shleifer and Vishny 1994;Dove 2017). Nations and controlling bodies have established laws and legal institutions (Tirole 1996;Devaraj and Patel 2017) to combat financial and political corruption (Alam 1989;Goel and Saunoris 2017) by identifying the key determinants of corruption (Dey 1989;Shleifer and Vishny 1993;Lee and Holoviak 2006).
We also reviewed the titles and abstracts of our sample to create a publication trend in each research stream during the last 51 years. Figure 6 shows that the first (the economic framework of crime and corruption) and third (the effect of corruption on aspects of national economics) research streams, which economists have been exploring extensively since 1990, peaked in 2015. The research on the second stream (legal institutions and corruption) has remained constant because researchers are concerned about the implementation of laws and regulations. The fourth (the combating and monitoring of corruption) and fifth (the determinants of corruption) streams are at the regeneration stage, as researchers are revisiting and exploring the measures and determinants of corruption and crime in this era of globalization and internationalization. However, the research on the sixth (political institutions and corruption) and seventh (the effect of corruption on firms) streams is underdeveloped and comparatively negelected. The keyword analysis in Figure 4 also confirmed the underdevelopment of the sixth and seventh research streams. Therefore, in Section 4, we recommend future research directions in these two areas.
Finally, we also summarized the data sources, measurements, and theoretical frameworks used in the 70 most influential papers in Table A4. This listing and summary of the critical aspects of these 70 papers should be helpful to researchers in producing additional quality research on the topic.

IV. Future research agenda
We used bibliometric citation and content analyses to identify future agendas (Bahoo 2020). First, we created a citation map ( Figure 5) using the top 70 papers. Second, through HistCite we determined the trending (between 2009-2019) and most influential articles and reviewed them. Third, we analysed recent articles published in 2017, 2018, and 2019 to avoid citation bias. Fourth, we used the idea of putting 'old wine in new bottles' (Dunning, Kim, and Park 2008, 158) to re-explore past frameworks, theories, models, and inferences concerning corruption and crime in developing, emerging, and developed countries. Finally, we converted these research   Table A5.

V. Conclusion
Corruption is a significant challenge for all societies and has a negative effect on their economic growth and development. It is one of the main reasons for the slow growth of developing countries. It exists in several forms: financial, non-financial, public, private, petty, and grand. It also occurs at the upper, middle, and lower levels of society in developed as well as underdeveloped countries. Due to globalization and the digitalization of the world economy, it has become an even more complex phenomenon. Thus, we must establish anti-corruption systems and revisit economic frameworks and models of corruption and crime. In addition, political corruption is a critical challenge for countries at all levels of development. Hence, it is essential to understand and explore the economic model of crime and corruption and its relationship to legal institutions, political institutions, and firms. These goals motivated our desire to summarize the literature on corruption in economics. While we used the full ISI WOK database, we recommend that future bibliometric studies on the topic use Scopus and Google Scholar database to validate our findings.

Disclosure statement
No potential conflict of interest was reported by the authors.

(i)-Key bibliometric terms used in the method (Kim and McMillan 2008) Terms Explanation/Details
Co-Citation Analysis This term means that the same content and topics in articles are citing each other.
Cartography Analysis Also called keyword analysis, it is based on the repetition of keywords in articles.
HistCite Software This programme is built to deal with the bibliometric data of ISI WOK. It accepts citation data as inputs and provides multiple outputs.
VOSviewer Software Another program that accepts ISI WOK bibliometric data and gives multiple outputs.  Becker (1968) in Table A3, which has the largest number of global citations in the ISI WOK).

TLC/t Total Local Citations Per
Year: Calculated as the TLC divided by time (i.e., Mauro 1995).

TGC/t Total Global Citations Per
Year: Represents the average citations per year (i.e., Becker 1968).

TLCe
Total Local Citations indicate the number of citations an article received during the last three years at the end of the period of the study. In our case, that was between January 2016 and December 2019.

TLCR
The total local cited references indicate how many times the references of the article or journal were cited by other articles in our sample of 4,488 articles.
(iii)-Sample selection process for bibliometric analysis (Bahoo, Alon,  Final Sample for Bibliometric Analysis (Screening of irrelevant and overlapping articles by reading titles and abstracts).
Corruption index Peter Neumann Collections in 1994.
Red Tape Index Business and Environmental Risk Intelligence (Rauch and Evans 2000) Corruption Index From Country Risk (Keefer and Knack 1997) Corruption Index World Competitiveness Report (Des and Tella 1997), (Ades and Di Tella 1999) Corruption Index World Bank Governance Indices (Swamy et al., 2001), (Faccio 2006) German Survey of Corruption Survey (Faccio 2006) Bribe Payment survey of Firms Ugandan Industrial Enterprise Survey (Fisman and Svensson 2007) Bribe Payment by Firms World Business Environment Survey (WBES) (Fan, Lin, and Treisman 2009) ii-Methods Method

References
Theory of Collective Reputations (Tirole 1996) Theory of Misgovernance (Banerjee 1997) Principal-Agent Theory (Hindriks, Keen, and Muthoo 1999) Schumpeter's Theory of Economic Development (Mo 2001) Theory of Optimal Law Enforcement (Polinsky and Shavell 2001) Public Interest Theories of Regulation (SimeonDjankov et al. 2003) Public Choice View Theory (SimeonDjankov et al. 2003) Corporate Governance Theory (Aidt, Dutta, and Sena 2008), (Knack 2001) Political Agency Framework of Besley (Ferraz and Finan 2011) Economic Theory of Corruption (Glaeser and Saks 2006) Standard Economic Incentive Theory (Olken and Pande 2012) Note: The table shows the data sources, methods, and theoretical frameworks applied in the 70 papers that create the citation map ( Figure 5).