"At a theoretical level, cash balance plans might seem impervious to movements in interest rates: Although rising rates would require a plan to pay larger benefits in the future, they would also reduce the time value of money, which might be expected to offset the increased benefit payout. However, this perspective misses the complex interest rate sensitivities inherent in cash balance plans' liabilities. Selecting plan assets with the goal of hedging against shifts in interest rates is just as important for cash balance plans as it is for defined-benefit pension plans."