How well are Social Security recipients protected from inflation?

"The NBER Bulletin on Aging and Health provides summaries of publications like this. You can sign up to receive the NBER Bulletin on Aging and Health by email. Social Security is widely believed to protect its recipients from inflation because benefits are indexed to the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W). However, the CPI-W may not accurately reflect the experience of retirees for two reasons. First, retirees generally have higher medical expenses than workers, and medical costs, in recent years, have tended to rise faster than the prices of other goods. Second, even if medical costs did not rise faster than the prices of other goods, as retirees aged, their medical spending would still tend to increase as a share of income; that is, each cohort of retirees would still see a decline in the real income left over for non-medical spending. We show that Social Security benefits net of average out-of-pocket medical expenses have declined relative to a price index for non-medical goods by almost 20 percent for men, and almost 27 percent for women, in the 1918 birth cohort. We also explore the extent to which indexing Social Security benefits to the CPI-E, an experimental measure of inflation for the elderly, would change these results"--National Bureau of Economic Research web site.