The House Social Security Subcommittee is holding a hearing at the moment. The witnesses' written statements have been posted. Here is a snippet from the written testimony of Kelly Ross, the Deputy Policy Director of the AFL-CIO:
The income replacement rate of today’s Social Security benefit is about one third lower than the OECD [Organization for Economic Coo-peration and Development, whose members are the major industrialized nations] average. The United States ranks 25th of 30 OECD countries in the share of the average worker’s earnings that is replaced upon retirement. For a medium earner retiring at age 65, Social Security benefits replace only 40 percent of their prior earnings, and this replacement rate will fall to 36 percent by 2030 because of the scheduled increase in the full retirement age.