Full retirement age for Social Security benefits is currently 66. This will soon start rising to 67. Most people go on Social Security retirement benefits before their full retirement age, a key fact that is usually lost when politicians talk of raising the retirement age. Those who go on retirement benefits before their full retirement age receive reduced benefits. This is called the actuarial reduction. This actuarial reduction was 20% when the full retirement age was 65 and is going up to 25% when the full retirement age reaches 67. Alicia Munnell and Steven Sass at the Center for Retirement Research at Boston College ask whether the actuarial reduction, which was first enacted more than 50 years ago, remains appropriate. Their conclusion is that it remains pretty close to actuarial equivalence. Their study is flawed, however, by the fact that they pretended that full retirement age was still 65. I don't understand why they did that. They certainly know what the current full retirement age is and doing the projections for full retirement age being 67 should not have been that difficult.