Gao, Yuqiang
Lu, Yuchen
Su, Chi-Wei
Zhang, Yu
Funding for this research was provided by:
National Social Science Fund of China (Nos.20BJL074)
Article History
Received: 13 July 2022
Accepted: 6 November 2022
First Online: 14 November 2022
Declarations
:
: This study involves the macro-data of human economy and society. All the data are from the official statistical yearbook. The data collection process is in line with the ethical and moral standards. The research method of this study is DID econometric method, and there is no need for ethical approval and animal experiment content. The author guarantees that the process, content, and conclusion of this study do not violate the theory and moral principles.
: We affirm that all authors have agreed on submission of the paper to <i>ESPR</i> and are fully aware of ethical responsibilities.
: The authors declare no competing interests.