Counting in lifespans is pretty senseless though. If your beef is with that then it would be much more effective to charge women more for social security than men. Smokers should get a social security discount along with obese people. Use actuarial tables from life insurance companies if you want it to be fair based on what people are expected to get out of it. Finally, the rich don’t really outlive the middle class by enough of a factor to matter (especially compared to the ones above).