http://reply.papertrans.cn/3/287/28608/28608-11.png
Submitted on: 30 October 2020.
Revised on: 19 November 2020.
Accepted on: 03 December 2020.
Stata Journal---SAGE PUBLICATIONS INC
http://reply.papertrans.cn/3/287/28608/28608-13.png
Submitted on: 19 September 2014.
Revised on: 14 October 2014.
Accepted on: 22 October 2014.
Stata Journal
Submitted on: 30 September 2005.
Revised on: 16 October 2005.
Accepted on: 10 November 2005.
Stata Journal---SAGE PUBLICATIONS INC
http://reply.papertrans.cn/3/287/28608/28608-16.png
http://reply.papertrans.cn/3/287/28608/28608-17.png
Submitted on: 06 February 2022.
Revised on: 27 February 2022.
Accepted on: 11 March 2022.
Stata Journal---SAGE PUBLICATIONS INC
Submitted on: 11 July 2014.
Revised on: 26 July 2014.
Accepted on: 04 August 2014.
Stata Journal
http://reply.papertrans.cn/3/287/28608/28608-20.png