NBER Publications by John Geanakoplos

One measure of the health of the Social Security system is the difference between the market value of the trust fund and the present value of benefits accrued to date. How should present values be computed for this calculation in light of future uncertainties? We think it is important to use market value. Since claims on accrued benefits are not currently traded in financial markets, we cannot directly observe a market value. In this paper, we use a model to estimate what the market price for these claims would be if they were traded.

In valuing such claims, the key issue is properly adjusting for risk. The traditional actuarial approach – the approach currently used by the Social Security Administration in generating its most widely cited numbers - ignores risk and instead s...

The heated debate about how to reform Social Security has come to a standstill because the view of most Democrats (that Social Security must be a defined benefits plan similar in spirit to the current system) seems irreconcilable with the proposals supported by many Republicans (to create a defined contribution system of personal accounts holding marketed assets). We describe a system of "progressive personal accounts" that preserves the core goals of both parties, and that is self-balancing on an ongoing basis. Progressive personal accounts have two critical features: (1) accruals into the personal accounts would be exclusively in a new kind of derivative security (which we call a PAAW for Personal Annuitized Average Wage security) that pays its owner one inflation-corrected dollar du...