We’ve gotten some interesting comments on our recent post about Social Security reform. In the post, we note that many reform options would slow the growth of benefits from one age cohort to the next, but not cut lifetime benefits relative to what people receive today. We didn’t focus on the specific issue of raising the retirement age, but used that option as an example of how benefits could continue to grow over time, but at a slower rate than what is currently being promised.

Will Social Security reform cut benefits? That’s highly unlikely. It’s more likely that reform will simply cut the rate of growth in benefits. Social Security reformers have often thought about reform in terms of the annual benefits they want to give people. The complication with this approach is that it ignores the enormous increase in the number of years that benefits have been paid as people retire much earlier and live longer than they did when Social Security was first created.

Following the flap over our Tax Policy Center colleague Bob Williams’s calculation that close to half of all families did not pay income tax in 2009, we thought it would be instructive to take a look at history. It turns out that over the past five decades, there have been other periods when families with close to average incomes have been exempt from the income tax, and that their current exemption levels were due to both Republican and Democratic efforts to reduce taxes for moderate-income households and to find alternatives to welfare.