In 1990, the ratio of people age 65 or older to people ages 20 to 64 in the United Kingdom was 26.7 percent. In the year 2050, this ratio is expected to be 45.8 percent. Assuming a payas-

you-go social security system, what change in the payroll tax rate between 1990 and 2050 would be needed to maintain the 1990 ratio of benefits to wages? If the tax rate were kept constant, what would happen to the ratio of benefits to wages?