A Progressivity Index for Social Security

Using the Social Security Administration's MINT (Modeling Income in the Near Term) model, this paper analyzes the progressivity of the Old-Age, Survivors and Disability Insurance (OASDI) program for current and future retirees. It uses a progressivity index that provides a summary measure of the distribution of taxes and benefits on a lifetime basis. Results indicate that OASDI lies roughly halfway between a flat replacement rate and a flat dollar benefit for current retirees. Projections suggest that progressivity will remain relatively similar for future retirees. In addition, the paper estimates the effects of several policy changes on progressivity for future retirees