. 2023 Dec 1;9(12):e22846. doi: 10.1016/j.heliyon.2023.e22846

Table 2.

Index system of city digital economy development index.

Primary index	Secondary index	Original index	Reference
City digital economy development index	Internet consumer groups	Number of Internet users	Liang et al. (2021), Zhao et al. (2020)
	Internet-related practitioners	Number of computer service and software employees
	Internet-related output	Telecom business volume
	Mobile Internet consumption volume	Number of mobile phone users
	Financial technology development	Peking University Digital inclusive financial index
	ABCDI innovation enthusiasm	Word frequency of 20 keywords such as artificial intelligence, blockchain, cloud computing, big data and Internet of things.	Chen and Zhang (2021)
	ABCDI innovation output	Number of applications for five digital technology patents, including ABCDI	Chen and Zhang (2021)

Note: The keywords are the same as those used by Chen and Zhang (2021).