Met Life has released an online calculator to help people determine the best age at which to claim Social Security benefits. This is obviously a step in the right direction, given how many people choose to claim at 62, the earliest age at which retirement benefits available. As best I can tell, the underlying approach is taken from SSA's own retirement calculators, though Met Life tweaks it with gender specific life expectancies and a generally snazzier interface (including Snoopy).
In short, the user inputs their age, earnings and gender, and the calculator estimates their benefits and life expectancies at different ages. Users compare claiming benefits at age 62 with claiming at some higher wage (say, the normal retirement age or age 70). The calculator then calculates the break-even age -- the age at which total benefits received are equal between the two claiming ages -- and the probability of the user surviving to the break-even age.
That said, and as much as I'm reluctant to criticize something which attempts to move in the right direction, there are a couple problems with the Met Life calculator.
First, if you're going to do a break-even analysis, total benefits should be calculated as a present value, meaning that the interest value of benefits is included, rather than simply summing benefits received in multiple years. Granted, SSA also simply adds up benefits, but this is wrong; no economist or actuary would do it this way.
Second, the break-even age approach isn't really the best way to choose a retirement age. Choosing your retirement age isn't a game in which you try to maximize lifetime benefits. Rather, you should retire at an age that provides you with an adequate income. Imagine, for instance, that you could maximize your lifetime Social Security benefits by claiming at age 62, but that your benefit at 62 would be below the poverty line. Would it make sense to claim then, or delay a few years to receive a higher benefit? Common sense says to delay, if you are able, but the considerations of benefit adequacy aren't accounted for in break-even exercises.
Third, the calculator doesn't take into account the annuity value of Social Security benefits. Retirement benefits are paid as an annuity, meaning that they last as long as you live. Annuities are very valuable compared to lump sums since they insure against the chance of outliving your assets. (So much so that even groups with below-average life expectancies, like black males, benefit from the Social Security annuity. See here.) By delaying claiming benefits, you're essentially "buying" more of the Social Security annuity. The insurance value of an annuity is hard to represent in an online tool, but it's worth bearing in mind research showing that a retiree would need a lump sum of around $150,000 to provide the same lifetime income security as an actuarially fair annuity with a premium of $100,000.
Fourth, the calculator doesn't tell the full story on the Social Security earnings test. It does note that early retirees with earnings above $13,560 will have their benefits reduced on a $1-for-$2 basis. What it doesn't tell is that at the full retirement age, Social Security not only stops reducing your benefits, but actually increases them to make up for benefits lost to the earnings test in earlier years. Over the course of a full retirement, total benefits are around the same. So the earnings test shouldn't discourage people from working while collecting benefits.
Overall, the Met Life calculator is a welcome addition to financial planning tools, particularly since it's designed to be easy to use. However, with improvements it could be significantly better.