A bibliometric analysis and visualization of blockchain

Highlights

• This paper made a structured and systematized review on blockchain by CiteSpace and VOSviewer.

• The main powers engaged in blockchain research were identified as authors, institutions, countries, and journals.

• Hot research topics and emerging trends that reflected research domains and core content were discussed in terms of blockchain research.

• Some conclusions were made and future research directions were recommended.

Abstract

Blockchain has received global concern as a research focus in recent years. It is a decentralized and unreliably distributed database technology. Numerous countries and researchers have successively applied blockchain in various fields. CiteSpace and VOSviewer were adopted as bibliometric analysis tools in this paper to obtain a comprehensive overview of blockchain technology and grasp the current research emphasis. The Web of Science core collection database was used as the primary source for data collection. The data were collected from 3826 articles published from 2013 to 2020. Specifically, the publication trends and categories might throw light on the development trends and current domains in terms of blockchain research. The most influential and productive authors, institutions, countries, and journals were involved in this bibliometric analysis. Theoretical knowledge and hot research topics on blockchain mainly ranged over “smart contract”, “bitcoin”, “security”, “ethereum”, and “cryptography”. A cluster analysis from the keyword perspective was carried out to obtain emerging trends and frontiers of blockchain. The results showed that future research should concentrate on management, blockchain technology, energy, machine learning, and smart home. Therefore, this paper assisted scholars and practitioners in getting a comprehensive understanding of the status quo and trends of blockchain research.

Introduction

As a relatively new technology, blockchain emerges in a variety of forms [1]. Blockchain has attracted wide attention from a considerable number of scholars who concentrate on blockchain and witness the explosive research progress in this field. Blockchain is a foremost tool to deal with all kinds of problems, including security, transportation, logistics, finance, and so on. Globally, the importance, security, and worldwide commercial impact of blockchain has created interest among researchers and inspired us to carry out this study. Based on this background, acquiring a clear systematic overview can help scholars to form insights into the characteristics of blockchain research.

What is blockchain? A common explanation is that blockchain is viewed as a decentralized scenario where untrusted members can interact with each other in a verifiable way [2], [3], [4]. The development of blockchain has experienced several stages; at the same time, the ethics and standards of the blockchain industry have also begun to attract attention. Blockchain standards came into existence in late 2017. Currently, most of blockchain standard activities focus on specifying and developing common frameworks, interfaces, and technical modules that work in self-contained or specific platform environments [5], [6], [7]. However, no regulations have been proposed by governments to implement blockchain in different fields. It is a good initiative to develop a standard framework for blockchain that could adapt to national legislation for all nation-states [8].

Blockchain technology is highly prevalent today, not only does it have a commercial impact on people’s work and lifestyle but also brings enormous opportunities to various fields. For example, health is an important field that the public concerns and blockchain technology are conducive to the dramatic improvement in health record management. Blockchain technology provides secure and efficient access to medical data by virtue of patients, providers, and third parties while preserving the patients’ private information [9], [10]. In data trading platforms, the blockchain solution is useful for helping to complement and mitigate limitations [11], [12]. The combination of the internet of things (IoT) and blockchain can support high-speed data transfer, especially in a 5G-enabled industrial environment during information collection and processing [13], [14]. As the most successful digital currency of blockchain, the wide adoption of bitcoin in finance and other business sectors will bring multiple business innovations and diverse research opportunities [15].

Many scholars have already conducted a great number of state-of-the-art studies on blockchain. However, most articles start from a single perspective: some scholars focus on its evolution [16], [17], some scholars focus on fundamental theories [6], [7], [8], and other scholars focus on its performance [9], [10]. Although these existing articles are valuable, they fail to objectively reveal the whole picture of blockchain or pay due attention to exploring hot research topics over the past few decades. Worse still, it is highly difficult to effectively organize, summarize, and quantitatively analyze the development of a specific field among a large number of studies on a large time scale in traditional review articles. Blockchain is an interdisciplinary research field that covers mathematics, finance, computer science, sociology, and communication science. In order to get a comprehensive understanding of the progress and hotspots of blockchain, a bibliometric analysis is needed.

The bibliographic technique is a quantitative analysis of books, articles, or other publications. In recent years, the bibliometric analysis has been applied in various professional fields to visualize the knowledge status, features, evolution, and emerging trends. This can help interested scholars with a lack of expertise in those fields which secures a full understanding [18]. Bibliometrics can present a considerable amount of academic research, which can be viewed from micro to macro perspective [19]. Based on bibliometric methods, the performance of various disciplines can be vividly observable. Therefore, this paper will use the maps generated by CiteSpace and VOSviewer to conduct a comprehensive and systematic analysis of blockchain research. CiteSpace usually works as an effective tool for researchers to extract network relations, research emphases, as well as research trends. VOSviewer can present detailed information on the literature, such as hot research topics.

This research is structured as follows. First, the data source and methods are introduced. Second, the bibliometric analysis results are presented from six main aspects, namely, publication outputs, categories analysis, countries and institutions cooperation analysis, author collaboration network and author co-citation network, co-citation journals analysis, and cited references analysis. Then, hot research topics, academic relations, and emerging trends will be summarized in specific fields. Finally, some conclusions and future research directions will be proposed. All in all, this paper will clearly and holistically show hot research topics and emerging trends of blockchain research, as compared to traditional literature review methods. This research will provide a useful guideline for scholars and practitioners who are interested in blockchain technology and seek cooperation opportunities with other scholars and research institutions by systematically collecting, characterizing, and analyzing research papers related to blockchain. Moreover, the predictions based on the bibliometric analysis can also provide ideas for future blockchain research. To achieve this aim, the following research questions (RQ) are worth answering. Table 1 lists all acronyms used in this paper.

RQ1: What are the overall publication trends and subject categories in terms of publication output?

Answering RQ1 would help researchers explore the development trends and status quo of blockchain research.

RQ2: Which countries, institutions, and authors have actively participated in blockchain research?

Answering RQ2 would enable researchers to identify international collaborations and potential collaborators on blockchain research. This would help explore the spatial distribution of articles.

RQ3: What are the most important cited journals that constitute the knowledge field of blockchain research?

Answering RQ3 would be expected to facilitate scholars to find suitable journals for publishing blockchainrelated papers quickly.

RQ4: What are highly cited references in blockchain research according to the number of citations?

Answering RQ4 would not only help researchers recognize significant documents, but also reveal influential and productive countries, organizations, and authors that are internally connected.

RQ5: What are the hot research topics and emerging trends discussed in blockchain papers?

Answering RQ5 would enable researchers to understand research domains and future directions clearly.