Funding for this research was provided by:
National Planning Office of Philosophy and Social Science (21ZDA104)
Received: 28 April 2021
Accepted: 17 July 2021
First Online: 3 August 2021
: Data used in this article comes from China Health and Retirement Longitudinal Study (CHARLS), which was an open data and own ethics approval and consent to participate.
: Not applicable.
: The authors declare that they have no competing interests. No conflict of interest exits in the submission of this manuscript, and manuscript is approved by all authors for publication. This work was original research that has not been published previously, and not under consideration for publication elsewhere. The authors listed have approved the manuscript that is enclosed.