In elementary school I learned about the power of compounding from a book titled One Grain of Rice. The story is about a king who promises to give a girl one grain of rice, and to double his gift every day for thirty days. Initially the gifts seem small, but by the end of the month more than one billion grains of rice have changed hands.
Similarly, an investment that initially seems negligible can go a long way given enough time to compound, and this lesson applies when saving for the future. In June, the Missouri State Employees’ Retirement System (MOSERS) decided to reduce its assumed return rate from 8% to 7.65%, meaning that altogether, the amount members will need to contribute next year will increase by almost $50 million. This extra cost today is hardly ideal, but in the long run it helps avoid a much larger bill.
Even though MOSERS made a mere 0.35% change to their expected return rate, the long-term impacts are huge. With a lower rate of return on its assets, a pension plan’s initial contributions must go up in order to keep benefits constant. In other words, a plan compensates for slower investment growth by putting more money in initially.
This change in funding highlights the risks associated with promising high investment returns. If a pension plan’s actual returns are lower than predicted, the result is a gap between available funds and the amount that has been promised to retirees. In the case of a guaranteed public employee retirement fund, taxpayers can be asked to cover this difference, and as the gap grows, so does the burden on taxpayers.
With a current funding ratio (current assets divided by the net present value of liabilities) of 67.8 percent, the plan (according to a Columbia Tribune report) will require $394.5 million this year to cover promised benefits. But this contribution amount will only be sufficient if investment returns match the 7.65% expectation. If investment growth is lower (in FY 2016 MOSERS generated a time-weighted return of only 0.3%), then the funding gap will widen over time. It’s easy to project high investment returns today, but making those predictions come true tomorrow is another story.
Slight adjustments in return assumptions can have tremendous impacts over an employee’s lifetime, so properly estimating investment returns is essential to a plan’s sustainability. (This essay by Andrew Biggs provides a comprehensive discussion of public employee pension funding for readers who want to explore this topic in more depth.) If pension benefits are guaranteed to employees, then the cost of these promised future benefits should be priced using returns on very low risk assets like government securities, which are currently far below 7.65 percent. Lowering the assumed return is a step toward greater transparency regarding the true costs of pension liabilities.