n the debate between economists and actuaries over how to value public sector pension liabilities, it seems we cannot even agree on the simple things.
In a recent commentary, Gary Findlay, executive director of the Missouri State Employees' Retirement System, asks that we consider the following pension financing formula:
Benefits = Contributions + Investment Income - Expenses
Mr. Findlay states that this simple formula is “equally applicable to defined benefit plans and defined contribution plans.” If DB plans have lower expenses or earn higher investment returns, which seems likely given economies of scale and professional fund management, then they are presumably a more efficient vehicle for generating retirement income.
Except for one problem: The most meaningful formula for a public sector DB pension plan is something like this:
Liabilities = Stocks + Put option - Call option = Benefits discounted at riskless rate.
Public pension plans invest in stocks and other risky assets, whose returns they count upon to meet their benefit liabilities. The returns from these investments are far from guaranteed. But because public pension benefits are guaranteed, they must be paid with 100% certainty.
This mismatch between the risk of the plan's assets and its liabilities means that the government — and therefore the taxpayer — has a contingent liability to backstop the plan's financing should investment returns fall short of expectations. This is effectively a put option, whose value can readily be priced. Mr. Findlay's exposition ignores this contingent liability, essentially treating a DB pension plan as if it were a DC plan, where the employer's obligation ends once the pension contribution is made. That, obviously, is not the case.
On the other hand, if investment returns exceed projected levels, the plan can keep the excess to fund future benefits. These gains are equivalent to selling a call option, which lowers the cost of funding future benefits. In practice, of course, excess returns often have been used to increase benefits rather than buttress the program's own finances.
The core insight of this formula, which economists and market participants recognize but pension plan executives and public pension actuaries ignore, is that the value of the implicit put option far exceeds that of the call option, meaning that the true costs of a public pension plan are significantly larger than one would infer from examining current contributions alone.
The reason is simple: Bad outcomes for investments correlate with bad outcomes for the economy as a whole, so — as we have seen throughout the country over the past several years — taxpayers would be called upon to increase pension funding when tax revenues are weak and unemployment high. As the 2010 Risk Assessment report of the office of the state actuary of Washington said: “Weak economic environments were correlated with weak investment returns. Lower investment returns created the need for increased contributions at a time when employers and members could least afford them.”
So-called “put-call parity” states that the sum of the initial investment, the put and the call, will equal the value of the future benefits discounted to the present at the riskless rate of return. In other words, this formula — which accurately presents what actually goes on in a public sector DB plan — points straight toward the so-called market valuation that pension executives, actuaries, investment advisers and public employee unions oppose.
Viewed through the lens of fair-market valuation, which at least roughly captures the approach taken in the private sector and for public employee plans in Canada and Europe, generous benefits funded with risky investments no longer seem to be such a bargain. Only once the true costs of public pension plans are understood can policymakers decide whether reduced benefits or increased taxpayer and employee contributions are appropriate.
Andrew G. Biggs is a resident scholar at the American Enterprise Institute, Washington.