Funding for this research was provided by:
national planning office of philosophy and social science (20CTY017)
Article History
Received: 29 July 2021
Accepted: 15 December 2021
First Online: 7 January 2022
Declarations
:
: The authors of this study had no competing interest to declare.
: The ethical approval and informed consent were not necessary as this study used publicly available data from China Health and Retirement Longitudinal Study (CHARLS) and authors had no contact to human-related materials. The Creative Commons Public Domain Dedication waiver (ExternalRef removed) applied to the data made available in this article, unless otherwise stated in a credit line to the data. Besides, the CHARLS research team obtained ethics approval (license numbers: IRB00001052–11015, IRB00001052–14030, and IRB00001052–17053) from the institutional review board of the Peking University National School of Development.
: All respondents provided written informed consent. If the respondent was illiterate, he/she would press the fingerprint after the interviewer dictated the content of the informed consent.
: This manuscript does not contain reproduced materials. Consent for publication is not required. All materials (tables and figures) are made by the authors on their own.