Examining Trends, Themes and Social Structure of Zakat Literature: A Bibliometric Analysis

This study specifically examines the development of zakat research from the aspects of five bibliometric indicators: (1) current development of zakat research and its distribution; (2) topic areas and themes in zakat research; (3) main contributors of zakat research; (4) current collaboration pattern in zakat studies; and (5) most influential documents in zakat literature. This study conducted a bibliometric analysis of 405 scientific papers on zakat recorded in the Scopus database until 2021. Various tools have been used – Microsoft Excel for frequency analysis, VOSviewer for data visualization, and Harzing’s Publish or Perish for metrics and citation analysis. This study finds that the number of zakat literature has increased significantly and consistently over the last ten years. The fields of Social Science, Business, Management, Accounting, Economics, and Finance are areas where zakat literature often appears in and is based in countries in the US, Europe and Asia. English is used in most zakat literature, along with several other languages like Malay, Arabic, German, Indonesian, and Turkish. Research results also indicate that the zakat literature is mainly found in the subject areas of economics, finance, management, and accounting. The use of keywords such as zakat, Malaysia, zakat institution, alleviation, distribution, zakat management, social welfare, education, efficiency, and human are widespread. This study also found that Malaysia, Indonesia, America, Saudi Arabia, and Britain have become the five countries that have played a major role in creating collaborative zakat research. The findings of this study provide important implications for improving the practice and reach of zakat globally. (j)


Introduction
Zakat is a Muslim obligation. Paying zakat is proof of a Muslim's faith and piety besides praying (Hayeeharasah et al., 2013). Unlike the other pillars of Islam, zakat has personal and social dimensions that function as pillars in economic development and welfare GJAT I JULY 2022 I VOL 12 ISSUE 1 I ISSN : 2232-0474 I E-ISSN : 2232.0482 www.gjat.my (Zaenal et al., 2016). Etymologically, zakat comes from the Arabic verbial noun, zakat. It means growing, clean and good. In the Qur'an, the term zakat, meaning to grow and develop, can be found in the Quran, 81: 18. The meaning of clean and good is contained in the Quran, 13: 19. The meaning of purifying is found in the Quran, 103: 9. In tandem with this, the renowned scholar, Yususf al-Qardawi (2000) in Abd Wahab and Abdul Rahman (2011), defines zakat as "to grow and increase", along with the connotation of cleaning. In legal application, zakat points to the "religious tax" issued on the property or person according to the Islamic terms.
Zakat has become one of the Islamic financial instruments that has significant roles in overcoming the problem of poverty (Amalia et al., 2020). The contribution of zakat to various social and humanitarian aids is increasing rapidly. According to a report released by the Islamic Development Bank, USD 5,000 billion of zakat funds were distributed globally in one year. Zakat institutions have played a good role in contributing to the Sustainable Development Goals (SDGs), especially in poverty alleviation, education, health care, environmental protection, and increasing job opportunities (Adebayo, 2020;Rassanjani, 2018). Zakat has developed into an interesting issue in any study of Islamic social finance. However, there is always the question of how to maximize the potentials of zakat so that zakat can have a significant impact on its recipients?
This research evaluates past zakat literatures through bibliometric analysis methods using quantitative and statistical approaches to generate distribution patterns of articles in certain issues and periods (Martí Parreño et al., 2016). The purpose of this study is to gain a deeper understanding of the zakat literature, particularly the role of zakat as an Islamic social finance instrument with its global reach and collaboration. This is critical in assisting academics in making recommendations for future study in the field of zakat. This research focuses on the bibliometric analysis of zakatrelated scientific publications hoping to answer the following research questions (RQs): RQ1: What is the current development of zakat research and its distribution? RQ2: What are the topic areas and themes in zakat research? RQ3: Who are the main contributors to zakat research? RQ4: What is the current collaboration pattern in zakat studies? RQ5: What are the most influential documents in zakat literature?

Bibliometric Analysis
According to Martí Parreño et al. (2016), bibliometric analysis is a study that uses quantitative and statistical methods to generate patterns of article distribution in certain problems and time periods. Bibliometric studies are used to present trends and patterns of one particular research topic (Sweileh et al., 2017). The bibliometrics analysis method is now popular as a research method to present the trends and impacts of a study (Sweileh et al., 2017). The indicators commonly used in bibliometric studies are publication classification, citation, authorship, publication impact, and country (Ahmi & Mohamad, 2019). Durieux and Gevenois (2010) divide the indicators of bibliometric studies into three, namely, quantity, quality, and structural indicators. Quantity indicator refers to the productivity of researchers. Quality indicators refer to the performance of the researcher's output as seen from the number of citations or citations per year, the total h-index or g-index, the citation score. Research quality indicators can also be seen from the impact of publications (IPP) and the impact factors (IF) (Ahmi & Mohd Nasir, 2019). As for, structural indicators, they refer to the relationship between publications, authors, and research

Previous Studies
Several studies have been conducted to analyze the trend of zakat research from various perspectives. Johari et al. (2015) first described the results of a study of zakat literature using content analysis techniques. Their study concludes that between 2003 and 2013, zakat research was dominated by issues related to zakat management, collection, distribution, and poverty alleviation programs. In the case of Rusydiana and Al Farisi (2016), zakat trends were analyzed for the period of 2011-2015. The study uses descriptive analysis techniques and concludes that zakat research was still dominated by discussions about zakat institutions (26%), distribution (22%), management (21%), poverty alleviation (20%), and collection (11%). Later, Niswah et al. (2020) carried out the study of zakat literature using bibliometric analysis methods. This research uses a database from Google Scholar and is limited to scientific works from ASEAN countries, providing an overview of the development map of zakat research, specifically in ASEAN countries.
There are also other several past bibliometric studies that focus on zakat or zakat related studies. The summary of these studies is listed in Table 1. One of them is a study by Abubakar and Aysan (2021). They both analyzed the trend of Islamic Social Finance (ISF) related studies, including zakat, using the bibliometrics approach from 1991 to 2020. Utilizing the Scopus database of 595 articles, they conclude that ISF studies have increased rapidly and are widely associated with the issue of Sustainable Development Goals (SDGs), where Indonesia and Malaysia are countries with the most significant contribution. Their finding was also confirmed by Rusydiana and As-Salafiyah (2021), who used Google Scholar of 391 ISF articles. They found that there had been a significant increase in the number of ISFthemed articles since 1979. They found that Hassan MK and Malaysia contribute to most of the ISF literature. While the bibliometrics analysis conducted by Abubakar and Aysan (2021) is quite comprehensive, their focus on the topic is broader instead of a specific focus on zakat only. Rusydiana and As-Salafiyah (2021), on the other hand, cover only coauthorship analysis and co-occurrences of keywords. Firmansyah et al. (2021), on the other hand, conducted a bibliometric study on publications using the term zakat or zakat involving 280 documents published in Islamic economics journals in Indonesia. Out of 280 documents, only 21 were related to zakat, which seems very limited to analyze using bibliometric analysis comprehensively. Al-Iqtishad, the Journal of Islamic Economics, Shirkah, Journal of Economics and Business, and Share: Jurnal Ekonomi dan Keuangan Islam, were found to be three of the most productive journals publishing articles on zakat in Indonesia. Based on the keywords and the title of co-occurrence, the study also concluded that the topic of zakat was less popular in Islamic economic journals.
Firmansyah's finding is however different from the conclusion made by the study conducted by Rusydiana and Nailah (2020) on 440 articles from various journals with the reputation of combining zakat with technology. Rusydiana and Nailah concluded that zakat and technology studies had increased every year, and that, among the most consistent researchers in this field was Timur Kuran.
Meanwhile, the words zakat, Islamic, and Indonesian are the most frequently used keywords in the study of zakat and technology. Nonetheless, although the bibliometric attributes conducted by Rusydiana and Nailah (2020) seemed very comprehensive, they were descriptive in nature. While their study covered both zakat GJAT I JULY 2022 I VOL 12 ISSUE 1 I ISSN : 2232-0474 I E-ISSN : 2232.0482 www.gjat.my and technology, their research protocols were not transparently disclosed.
From another perspective, Alshater et al. (2021) conducted their research using the Scopus database of 224 documents published from 1969 to 2020. Their study focused on the most influential articles, authors, organizations, and countries, as well as citation analysis, co-citations analysis, and keywords occurrences in zakat research. Still, not unlike Abubakar and Aysan's and Rusydiana and Nailah's, Alshater et al. (2021)'s coverage might have appeared comprehensive, yet, their study had not disclosed the impact of publications using indicators such as total citations, number of cited papers, h-index or g-index.
Nor Paizin et al. (2021) also conducted a bibliometric analysis on zakat. Their findings were however very descriptive based on charts originally produced by Scopus and limited to the theme of the co-word analysis. The method used in their study seems not clear enough. In the abstract, they used the term zakat payment. In the method, they focus on the zakat usage-the criteria used for the selected journals were also quite blurry resulting in the uncertain credibility of the findings. As for Anam et al. (2021), their study only focused on zakat studies published in journals ranked from quartile one (Q1) to quartile three (Q3). Such limitation does not really present the picture of zakat literature as a whole.
It seems apparent that, while many bibliometric studies have been conducted on zakat in the past, their coverage remains not comprehensive enough. Many bibliometric perspectives have not been deeply or clearly covered. The studies listed in Table 1 have their own limitation in terms of the coverage, such as, the sources and scope, as well as, issues on research protocols. In Alshater et al. (2021)'s case, this study surprisingly found that there were 405 more articles just within an additional one-year period than the 224 articles Alshater et al. obtained and analyzed. Using a larger number of articles will arguably provide richer information than previous researches. Most of the past studies were also too descriptive in nature. The present study tries to fill these gaps and update the latest trends in zakat studies. "islam" or islamic" and "social finance" or "social-finance" and "waqf" and "zakat" and "microfinance" or "micro-finance."  595 Annual scientific production, keywords co-occurrence network and overlay, most relevance sources, source impact, most productive countries, citation map by country, author's production over time, authors impact, coauthorship network, corresponding authors country, most globally cited documents and bibliographic coupling.  Publication trends, core journals, co-author network, citations, keywords network, overlay and density visualization.

Data Source
This study is based on bibliometric analysis methodologies, which employ quantitative and statistical approaches to establish patterns of article distribution in certain issues and time periods (Martí Parreño et al., 2016). Scopus database was used as the main source of the bibliographical data of the zakat literature. Scopus is the choice because it has several advantages, such as the availability of an advanced searching function, indexing more than 5000 publishers, and having adequate article quality standards (Martín-GJAT I JULY 2022 I VOL 12 ISSUE 1 I ISSN : 2232-0474 I E-ISSN : 2232.0482 www.gjat.my Martín et al., 2018;Gusenbauer & Haddaway, 2020). Scopus now contains a literature database that includes 23,700 peer-reviewed journals with 24,000 titles, 360 trade publications, 750 book series, 195,000 nonserial volumes, and 60 million entries from a variety of subjects (Wahid et al., 2020). This massive database is meant to give a comprehensive picture of zakat studies across the world. Four hundred five documents were examined based on preset keywords.

Data Collection
The research process begins by identifying the keyword "zakat" or "zakah" in the Scopus database based on the title of the article. This study accommodates all types of documents obtained from the Scopus database between 1969 and 2021 as of January 24, 2022. Thus, the search query TITLE ("zakat" OR "zakah") has been performed in the Scopus database. The search produced 405 documents of the zakat literature. Since the search query has been conducted using the search within the article title only, we can assume that all the documents obtained are really about the zakat, which is the main topic of this study. After the screening, no documents have been removed. So, all 405 documents were eligible in this bibliometric study. Figure 1 illustrates the flow of the search strategy of this study.

Data Analysis
This study utilizes the analysis function on the Scopus database and tools such as Microsoft Excel for mathematical calculations such as frequency of published documents and to design relevant charts and graphs; Publish or Perish for publication impact and performance based on selected metrics; and VOSviewer for mapping and visualization of the bibliometric networks. In order to answer the RQs stated in the earlier section, this paper has strategized the data analysis accordingly. The first analysis covered the analysis of publications by year, source and type of document, and source title to answer the RQ1. We analyze the subject areas and the author's keywords to answer the RQ2. We present the network visualization map of co-authorship among authors and countries to answer the RQ3. Finally, the top 20 highly cited documents were revealed to answer the RQ4.

Results
This section discusses the results based on the research questions that have been highlighted in the introduction section.

Development of Zakat Research and Its Distribution
To answer the RQ about the development of zakat research and its distribution, this study analyses the following data: (a) publications by year, (b) the source and type of document, and (c) source title.

Topic Areas
This result analyses the topic areas of zakat research in terms of (a) subject areas and (b) author's keywords. This result also tends to answer the RQ on the topic areas and themes in zakat literature.

Subject area.
This study identifies documents based on their field of study of the source titles where they have been published. The result shows in Table 5. The data show that research on zakat has emerged in various fields of study. Most studies on zakat are published in the journal's categories under the field of social science with 150 documents (37.04%), economics, econometrics, and finance with 136 documents (33.58%), business, management and accounting (131; 32.35%), and art and humanities (106; 26.17%). The result also shows that the study on zakat has been published in the journal categorized under other subject areas such as engineering, computer sciences, decision science, environmental science, and many others.  Figure 3 presents a visualization of the author's keyword network with at least three occurrences each. This study uses VOSviewer and software to build and visualize a bibliometric network. The color, circle size, text size, and thickness of the connecting line show associations with other terms. Keywords of the same color, for example, are frequently included together.
Based on Figure 3, it is known that the word zakat is the keyword most commonly associated with other words such as Malaysia, poverty, zakat institutions, Indonesia, distribution, and management as keywords in zakat research. Based on the network visualization map of author keywords, 90 items have been formed with 12 clusters, 363 links, and 590 total link strengths.  The total unique author's keywords found in this study are 880 words.  The third evolution of zakat research occurred in 2018. The color change from light blue to green indicates a significant shift in the theme of zakat research. The theme of the accountability of zakat institutions is the main issue in this evolution. Keywords such as zakat Institution, Zakat Accounting, Accountability, and Financial Reporting, are the dominant keywords. The keyword Indonesia is widely used in this phase. This shows that a lot of research has been carried out in Indonesia. The fourth evolution occurred in 2019. The theme of zakat research in this phase raised the issue of economic empowerment. The use of keywords such as Mustahik, Empowerment, Welfare, Charity, and Islamic Finance was found in the zakat literature at that time. The last phase of the evolution of the zakat research theme is 2020. The research theme in this phase is the issue of Good Zakat Governance. The zakat literature discusses a lot about strengthening the governance system of zakat institutions related to information technology. Therefore, keyword types such as Digital Zakat, Social Capital, and UTAUT are often found in the current zakat literature. No exception, the keyword COVID-19 is also widely found. Of course, this is very relevant if it is related to the use of information technology, especially digital zakat, during the COVID-19 pandemic. Therefore, this theme is still relevant for researchers to do in the next few years.

Most Productive Contributors in Zakat Studies
To answer the RQ on the top contributors in zakat studies, we analyze the productive (a) authors, (b) institutions, and (c) countries that contribute most publication on zakat until 2021. Based on Table 7, it can be seen that researchers from Malaysia have dominated the productivity in the zakat literature. Ram Al-Jaffri Saad from Universiti Utara Malaysia lead the list followed by Saeed Awadh Bin-Nashwan who is also from Universiti Utara Malaysia, Fuadah Johari from Universiti Sains Islam Malaysia and Hairulnnizam Wahid from Universiti Kebangsaan Malaysia. This finding also confirms several previous studies, such as Alshater et al. (2021) andNor Paizin et al. (2021). Based on this fact, there is an opportunity for researchers from other countries to collaborate so that zakat research can be extended. The zakat research cannot necessarily be conducted from the perspective of the Islamic countries but can also be conducted in countries with a significant number of Muslims. The findings also show the literature gaps where most of the zakat studies focus more on the Asian region (such as Malaysia and Indonesia) than other Islamic countries from the Middle East region.   These results also indicate that the topic of zakat has become a field of interest not just from Islamic countries but also from non-Islamic countries.

Collaboration Patterns
This study also provides a network visualization of co-author mapping among different authors (see Figure 5). This map employs a fractional counting approach and is based on information from writers who have written at least one zakat-related document.  Next, Figure 6 shows a map of the collaboration network based on their affiliated countries. We selected all countries with a minimum of one document regardless of the number of citations received. A network visualization map as per Figure 6 is generated based on the fractional counting method. The map shows three main clusters that exist.
Details of these clusters are also shown in Table 10. Although some of the countries' names are not seen on the map, it, however, can be visualized in this    3  3  3  India  3  2  4  Tunisia  3  2  4  Spain  3 1 1 Table 11 listed the 20 most influential documents in zakat studies based on the number of citations they have received so far. The two most frequently cited documents are the study of zakat conducted by Scott (1987) with the title "Resistance without protest and organization: Peasant opposition to the Islamic zakat and the Christian tithe". This study is the most cited document considering that this study is the first published study of zakat. Other widely cited documents are studies that raise issues of Efficiency (Abd Wahab & Abdul Rahman, 2011), the role of zakat (Kuran, 2003), distribution management (Rosli, 2018), and zakat empowerment programs (Mohit & Nazyddah, 2011).

Most Influential Documents
If we look more closely at the data in Table  11, it can be identified that the document with the most citations is the research that has become a reference by many researchers at every stage of its evolution. In the early stages of the evolution of zakat research, many researchers raised the theme of zakat in the theological, historical perspective, as well as the basic concept of zakat, for example, Scott (1987), Kuran (2003), Calder (1981) and Jehle (1994). The results of their research are ultimately a reference for future researchers. The evolution of the theme of zakat research from a theological perspective to the institutional aspect has produced several  (Rosli, 2018), have become references for many studies with this theme. Next, we can also see that the literature that is widely referenced is research that talks a lot about empowerment. This shows that there is an evolution towards the theme of zakat research. Where at that time, the theme of empowerment was a theme that was widely discussed by researchers. Some of the literature that is widely referenced includes discussing zakat compliance (Saad & Haniffa, 2014), corporate zakat (Owolabi Yusuf & Derus, 2013), and corporate social responsibility (Javaid & Al-Malkawi, 2018). Meanwhile, one last piece of literature that is widely referenced is research (Syed et al., 2020) which raises the theme of Artificial Intelligence (AI). This study became a reference for many researchers who raised the theme of information technology in zakat institutions. Currently, the AI theme is a popular topic in various research fields, including zakat research, and will continue to develop as information technology advances. Therefore, for zakat researchers, this topic should be an open area for research.

Conclusion
Our findings show that the first literature on zakat was published in America in 1969. The emergence of zakat research originated from Western scholars, spreading slowly to countries in Asia, Africa, and Europe. The growth of research on zakat stagnated until 2008, starting to increase significantly and consistently from 2011 to 2021. Social science, business, management, accounting, economics, and finance are areas where zakat literature often appears and is based in Europe and Asia. In addition, most zakat documents are published in English and several other languages such as Malaysian, Arabic, German, Indonesian, Slovak, and Turkish.
Our observations also find that the subject areas, and keywords in the zakat literature, are dominated mainly by social domains related to economics, finance, management, and accounting. Some of the popular keywords used, among others; (a) zakat, (b) Malaysia, (c) zakat institution, (d) poverty alleviation, (e) zakat distribution, (f) zakat management, (g) social welfare, (h) education, (i) efficiency, and (j) human. The keywords poverty alleviation, social welfare, and education seem to have become the focus of researchers related to the issue of management of zakat institutions.
On the other hand, this study has revealed that Malaysia, Indonesia, America, Saudi Arabia, England, Pakistan and Nigeria have become five countries that play a major role in creating collaborative zakat research among scholars, institutions, and countries. Twentyfive countries have collaborated to create 9 clusters and 41 research networks. This study identifies that healthy cross-border collaboration is still limited to countries in GJAT I JULY 2022 I VOL 12 ISSUE 1 I ISSN : 2232-0474 I E-ISSN : 2232.0482 www.gjat.my one region. There is still limited collaboration in zakat research with countries in Europe, America, Australia, and Africa. This might lead to a fractured conception of zakat, with the most important geographical, economic, institutional, and cultural components.
During our examination of nations, organizations, authors, and citations, we discovered that, initially, the zakat literature with the greatest citations was written by writers from South Asian countries., namely India, Pakistan, Bangladesh (Apte, 1969;Begum, 1993;Mohammad, 1991) and two documents from the UK (Calder, 1981;Scott, 1987). But now, zakat literature has spread to various countries, including Europe, America, Africa, and all Asian countries. Even today, zakat literature from writers from countries in Southeast Asia, such as Malaysia and Indonesia, has dominated and accounted for more than 70% of zakat literature.
We accept that the Scopus database and the usage of keywords in document titles are the only sources of information for this study. Other databases, such as Google Scholar and Web of Science and other papers that address zakat but do not utilize the keywords we employ, are not taken into account. Despite these flaws, this research helps to better understand zakat research patterns. Each metric demonstrates progress in this field of study, which might lead to further research possibilities. This study also adds to and complements the previous findings in the study of zakat using the bibliometric method.