Look at the table values for the present value of an annuity, as shown on pages 86 93. You can see that as the interest rate increases, the value of the annuity goes down. You need to put aside less money to buy the same payments because your money earns at a greater rate. As the number of periods increases, the value of the annuity increases. More money is always worth more money, even if the eventual payment is a long time off. However, the value increases at a decreasing rate, because the additional payments are due at increasingly distant times and have ever-decreasing present values.