Figure 3
The horizontal axis is labeled “Relevance degree (Centrality)” and the vertical axis is labeled “Development degree (Density).” A dashed horizontal and a dashed vertical lines divide the plot into four quadrants labeled as follows: top-left is “Niche Themes,” top-right is “Motor Themes,” bottom-left is “Emerging or Declining Themes,” and bottom-right is “Basic Themes.” The graph shows several clusters of keywords plotted on a thematic map across the four quadrants. In the top-left quadrant labeled “Niche Themes,” there are two clusters. The first cluster include the keywords “agriculture,” “farms,” “statistics,” and “threshold effect” and the second cluster includes “education,” “numerical model,” “engineering research,” and “income.” Along the vertical dashed line near this quadrant, additional keywords appear including “costs,” “covid-19,” “financial crisis,” and “financial markets.” In the top-right quadrant labeled “Motor Themes,” a cluster contains the keywords “panel data,” “carbon,” “carbon emission,” and “emission control.” In the bottom-left quadrant labeled “Emerging or Declining Themes,” there are two clusters. The first includes “artificial intelligence,” “financial service,” “block-chain,” and “blockchain.” The second includes “quality control” and “technology adoption.” In the bottom-right quadrant labeled “Basic Themes,” there are two clusters. The first cluster includes “finance,” “china,” “digital finance,” and “innovation.” The second cluster contains “financial market,” “financial system,” “financial services,” and “banking.” A cluster with keywords “economic growth,” “information and communication technology,” “economic and social effects,” and “empirical analysis” is present on the horizontal line between “Motor Themes” and “Basic Themes.” A small cube icon resembling a logo appears in the lower-right corner of this quadrant.Thematic map based on the research domain of digital finance. Note: The map illustrates themes categorized into four quadrants: motor, niche, emerging/declining and basic. Centrality = thematic relevance; Density = level of internal development. Source(s): Authors’ own work (extracted from VOSviewer software)