Papers on the rate of returns for government-run pension plans I'm looking for papers studying the implied rate of return for various government pension programs around the world. Both historical and expected returns. Or any study that looks at the taxes for the pension scheme, and what participants receive.

I have searched for papers on Google Scholar and found a few (on the state pension systems in USA, Germany, and Sweden), but now the searches give little yield.

Any help would be appreciated. Thanks in advance!
Here are the papers I've already found, in chronological order.

USA


Boskin, Michael J., et al. "Social security: A financial appraisal across and within generations." (1986). 
Boskin, Michael J., and Douglas J. Puffert. "The financial impact of social security by cohort under alternative financing assumptions." (1987).
Duggan, James E., Robert Gillingham, and John S. Greenlees. "Returns paid to early social security cohorts." Contemporary Economic Policy 11.4 (1993): 1-13.
Leimer, Dean R. Cohort-specific measures of lifetime net social security transfers. No. 59. US Dept. of Health and Human Services, Social Security Administration, Office of Research and Statistics, 1994.
Beach, William W., and Gareth G. Davis. Social Security's rate of return. Heritage Foundation, 1998.
Leimer, Dean. "Cohort-specific measures of lifetime social security taxes and benefits." (2007).


GERMANY


Schnabel, Reinhold. "Rates of return of the German pay-as-you-go pension system." FinanzArchiv/Public Finance Analysis (1998): 374-399.
Wilke, Christina Benita. "Rates of Return of the German PAYG System-How they can be measured and how they will develop." (2005).
Lüthen, Holger. "Rates of return and early retirement disincentives: evidence from a German pension reform." German Economic Review 17.2 (2016): 206-233.


OTHER


Auerbach, Alan J., and Ronald Lee. "Welfare and generational equity in sustainable unfunded pension systems." Journal of public economics 95.1-2 (2011): 16-27.