A reader writes in, asking:

“The age old question: Lump Sum or Monthly Payment? A few years ago it was considered lunacy in the office for anyone who took the Monthly vs Lump option. With increasing interest rates the Lump option today is significantly smaller than last year – and stability of guaranteed income the Monthly is looking more attractive in today’s climate. How does someone figure out – optimal choice, not just Lump vs Monthly, but, if you go Monthly understanding the financial tradeoff on choices of survivor percentage, to “X year Certain and Life Annuity” and “Cash Refund Unpaid Balance” payment options. How do you figure out what is the better option – or at least what you are trading off on one vs the other?”

For pension decisions, when looking at the decision for a client, I typically take two approaches.

First is the quick/easy approach, which is to compare via an online annuity quote provider, such as immediateannuities.com. I’ll put in a given premium (e.g., $100,000), and see what is the annual percentage payout available, for a person who is the age in question (or for a couple of the applicable ages).

And then that percentage payout can be compared to the percentage that is available as the pension annuity option (i.e., annual income, divided by alternative lump sum). Sometimes what you’ll see is that, relative to what’s available in the private marketplace, the pension annuity option is a very good deal or a very bad deal, which then makes the decision relatively easy. Often though, the answer is that it’s a roughly “fair” deal.

And I’ll repeat that process for each pension option for which there is a comparable annuity option. Sometimes you’ll find that one of them is clearly the best deal, actuarially. One limitation of the above method though is that there are often a broader range of pension payout options (especially survivor options) than comparable options on annuity websites.

The second approach is to do an expected present value comparison. For a single person, that’s essentially asking what is the person’s life expectancy, and then “discounting” those expected payments (from the lifetime annuity option) to determine the present value, and see whether that is meaningfully higher or lower than the amount available from the lump sum. (This article has steps for doing a present value calculation in Excel.)

For a married couple, it’s the same general concept but a bit more involved. In that case, I use this spreadsheet (credit to #Cruncher on the Bogleheads forum) to calculate how likely each of the mortality scenarios is for each year going forward (i.e., probability both people are alive, probability only personA alive, probability only personB is alive, probability neither person is alive). And then for each year I multiply those probabilities by the benefit payment in question (i.e., payment if both people are alive, payment if only personA is alive, and payment if only personB is alive). And then I discount all of those probability-weighted cash flows back to their present value, and see how that compares to the lump sum option.

When doing an analysis similar to the above, it’s important to use varying mortality assumptions to see how sensitive the results are to such changes. And the results should be treated as a rough conclusion, because we* don’t* know how long you (and/or your spouse, if applicable) will live. So, for example, if two options are only a few percentage points apart in terms of expected present value, rather than concluding, “ah, *this* option is better,” I think a more appropriate conclusion is, “these two options are very similar.”

In addition, all of the above is purely dealing with the actuarial expected payout. And there are two other factors to consider as well: taxes and longevity risk.

With the Social Security filing decision, tax planning is usually a point in favor of waiting (because Social Security benefits are themselves tax-advantaged). But with the pension decision, it could point in either direction, or neither.

From a longevity risk point of view, the annuity option (if married, the annuity option with the highest survivor benefit) is generally the better option, though as per the above discussion it could make sense to take the lump sum and buy an annuity elsewhere. In addition, for people whose desired retirement spending is very modest relative to available resources, longevity risk is already very low. So a further reduction in that risk isn’t particularly valuable.