Suppose that in a certain defined benefit pension plan,

a) Employees work for 45 years earning wages that increase at a real rate of 2%.

b) They retire with a pension equal to 70% of their final salary. This pension increases at the rate of inflation minus 1%.

c) The pension is received for 18 years.

d) The pension plan's income is invested in bonds that earn the inflation rate plus 1.5%.

Estimate the percentage of an employee's salary that must be contributed to the pension plan if it is to remain solvent. (Hint: Do all calculations in real rather than nominal dollars.)