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OPTIMAL MIX BETWEEN PAY AS YOU GO AND FUNDING FOR PENSION LIABILITIES IN A STOCHASTIC FRAMEWORK

Published online by Cambridge University Press:  14 August 2015

Pierre Devolder  and
Roberta Melis
Pierre Devolder
Affiliation:
Institute of Statistic, Biostatistic and Actuarial Science (ISBA), Université Catholique de Louvain (UCL), 20 Voie du Roman Pays, 1348 Louvain la Neuve, Belgium E-Mail: pierre.devolder@uclouvain.be
Roberta Melis
Affiliation:
Department of Economics, Universitas Mercatorum, via Appia Pignatelli 62, 00178 Roma, Italy E-Mail: r.melis@unimercatorum.it and CRENoS Centre for North South Economic Research
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Abstract

This paper addresses the financing of public pensions in a stochastic environment. Traditionally, funded and unfunded pension schemes have been viewed as opposite solutions for the first pillar of public pensions. However, more recently countries as Sweden and Poland have explored mixed solutions that combine pay-as-you-go (PAYG) with funding mechanisms. The aims of this paper are to examine the rationality of such a combination using portfolio theory arguments and to find the optimal split of the contributions between the two systems. We first introduce the classical deterministic model leading to the well-known Samuelson–Aaron rule according to which diversification is never optimal. We then introduce different stochastic models in which the main processes (wage growth, population growth, financial rate of return) are random. In particular, we obtain conditions on parameters to justify diversification and explicit optimal sharing between PAYG and funding. We also introduce the possibility of investing in several financial assets and explore the impact of introducing systematic longevity risk.

Keywords

Pay as you gofundingdiversificationportfolio theory
Type
Research Article
Information
ASTIN Bulletin: The Journal of the IAA , Volume 45 , Issue 3 , September 2015 , pp. 551 - 575
Copyright
Copyright © Astin Bulletin 2015 

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References

Aaron, H. (1966) The social insurance paradox. Canadian Journal of Economics and Political Science, 32 (3), 371–374.CrossRefGoogle Scholar
Bilancini, E. and D'Antoni, A. (2012) The desirability of pay-as-you-go pensions when relative consumption matters and returns are stochastic. Economics Letters, 117 (2), 418–422.CrossRefGoogle Scholar
De Menil, G., Murtin, F. and Sheshinski, E. (2006) Planning for the optimal mix of paygo tax and funded savings. Journal of Pension Economics and Finance, 5 (1), 1–25.CrossRefGoogle Scholar
Dutta, J., Kapur, S. and Orszag, M. (1999) How to fund pensions: Income uncertainty and risk-aversion. Birkbech Economics Working Papers, No 99–03.Google Scholar
Dutta, J., Kapur, S. and Orszag, M. (2000) A portfolio approach to the optimal funding of pensions Economics Letters, 69, 201–206.CrossRefGoogle Scholar
Guigou, J.D., Lovat, B. and Schiltz, J. (2012) Optimal mix of funded and unfunded pension systems: The case of Luxembourg. Pensions: An International Journal, 17 (4), 208–222.CrossRefGoogle Scholar
Knell, M. (2010) The optimal mix between funded and unfunded pension systems when people care about relative consumption. Economica, 77, 710–733.CrossRefGoogle Scholar
Matsen, E. and Thogersen, O. (2004) Designing social security — a portfolio choice approach. European Economic Review, 48, 883–904.CrossRefGoogle Scholar
Meijdam, L. and Ponds, E. (2013) On the optimal degree of funding of public sector pension plans. Discussion Paper Tilburg University, Center for Economic Research, Vol. 2013-011.CrossRefGoogle Scholar
Melis, R. and Trudda, A. (2012) Solvency indicators for partially unfunded pension funds. Investment Management and Financial Innovations, 9 (4), 71–77.Google Scholar
Merton, R.C. (1983) On the role of social security as a means for efficient risk sharing in an economy where human capital is not tradeable. In Financial Aspects of the United States Pensions System (eds. Bodie, Z. and Shoven, J.), pp. 325–358. Chicago: University of Chicago Press.Google Scholar
Miles, D. (2000) Funded and unfunded pension schemes: Risk return and welfare. CESifo Working Paper, No 239.CrossRefGoogle Scholar
Samuelson, P.A. (1958) An exact consumption-loan model of interest with or without the social contrivance of money. Journal of Political Economy, 66 (6), 467–482.CrossRefGoogle Scholar
Thogersen, O. and Bohlerengen, K. (2010) Alternative risk-sharing mechanism of social security. FinanzArchiv/Public Finance Analysis, 66 (2), 134–152.CrossRefGoogle Scholar
Van Praag, B. and Cardoso, P. (2003) The mix between pay-as-you-go and funded pensions and what demography has to do with it. CESifo Working Paper, No 865.Google Scholar