1) Over the next 75 years, Social Security’s shortfall is equal to about 0.7 percent of GDP. Source (PDF).

2) For the average 65-year-old retiring in 2010, Social Security replaced about 40 percent of working-age earnings. That “replacement rate” is scheduled to fall to 31 percent in the coming decades. Source.

3) Social Security’s replacement rate puts it 26th among 30 Organization for Economic Cooperation and Development nations for workers with average earnings. Source.

4) Without Social Security, 45 percent of seniors would be under the poverty line. With Social Security, 10 percent of seniors are under the poverty line. Source.

5) People can start receiving Social Security benefits at age 62. But the longer they wait, up until age 70, the larger their checks. Waiting to 66 means checks that are 33 percent larger. Waiting to 70 means checks that are 76 percent larger. But most people start claiming benefits at 62, and 95 percent start by 66. Source.

6) Raising the retirement age by one year amounts to roughly a 6.66 percent cut in benefits. Source.

7) In 1935, a white male at age 60 could expect to live to 75. Today, a white male at age 60 can expect to live to 80. Source.

8) In 1972, a 60-year-old male worker in the bottom half of the income distribution had a life expectancy of 78 years. Today, it’s around 80 years. Male workers in the top half of the income distribution, by contrast, have gone from 79 years to 85 years. Source.

The conclusions I draw from these numbers are:

1) Social Security’s 75-year shortfall is manageable. In fact, it’d be almost completely erased by applying the payroll tax to income over $106,000. Source (PDF).

2) Most opinion elites — Simpson being one good example, and the U.S. Senate being another — show a very strong preference for working as long as possible. Most Americans show a very strong preference for retiring as early as possible. Elites who enjoy their jobs need to be very careful about generalizing their experience to people who don’t enjoy their jobs. More bluntly: Raising the retirement age is the worst of all possible options for reforming Social Security. It’s not only regressive, but it also falls most heavily on those with the worst jobs. Means-testing would be much better.

3) Social Security is fairly stingy and getting stingier. We also know most 401(k)s are underfunded, and the same goes for many defined-benefit pension systems, both public and private. We need to be very careful not to “solve” the Social Security problem by worsening a broad retirement-security problem, and that requires approaching Social Security as part of our retirement-security infrastructure rather than simply as a budgetary question. Here are some ideas on how to do that.