Social Security - A better plan?

Seems to me that we can guarantee the solvency of social security without higher taxes, lower benefits, or private or personal accounts by adjusting the retirement age so that it matches the expected income from payroll taxes, with adjustments every 5 years or so to account for demographic and revenue changes. I haven't done the math, but there are 3 variables (maybe more) that affect the solvency of social security. The are 1) the retirement age or the age at which benefits start; 2) the payroll tax revenue from current workers; and 3) the benefits to be paid to retirees. If we are unwilling to either raise taxes or reduce benefits, the only thing left to change is the retirement age.

Here are some sobering statistics:

Percent of pop > 65				Average Remaining Life Expectancy for Those Surviving to Age 65
1930	5.4%			1940	M 12.7	F 14.7
1940	6.3%			1990	M 15.3	F 19.6
1990	12.6%
2000	12.7%
Percentage of Population Surviving from Age 21 to Age 65				Number of Americans Age 65 or Older
1940	M 53.9%	F 60.6%		1940	9.0m
1990	M 72.3%	F 83.6%		1990	31.9m

The impacts as I see them are as follows. There may be others. 1) The age at which benefits start may well have to be raised to age 75 or more. 2) If people want to stop working at an earlier age, they will have to have some sort of savings in a private or personal account. This is already true for those who retire early now, but it may spur the savings habit.