The 30-60-90 Approach to Retirement Planning, Part 1: Estimating Monthly Expenses

This is something that I have been working on in the past couple of months, and I feel that now is a good time to share it with you.

The right way to do retirement or financial planning is to estimate future annual earnings and expenses, before and after retirement, using a set of assumptions as I have demonstrated here and here. The problem with this approach is that it may be too complex and daunting for many individuals. The 30-60-90 framework is a simple, easy to use and understand tool for estimating the amount one needs to save in order to cover retirement expenses. Despite its simplicity, the approach is well grounded in theory as it considers important considerations such as inflation and investment returns.

30-60-90?

The name comes from the premise that an individual would start to save for retirement at 30, retire at 60, and pass away at 90; the implication that the saving period equals the retirement (or zero income) period equals 30 years makes a simpler analysis possible. Being in a 30-60-90 situation means that you have 30 years to earn what you expect or aim to spend in your 30 years of retirement. Ignoring inflation and interest for the moment, this means that by the time you retire you will have accumulated 3 million pesos in wealth, which you will then use in equal increments of 100,000 per year in the next 30 years and your wealth will have been depleted to zero at the end of your 90th year. (While the 30-60-90 scenario may not perfectly fit everyone, it's a good enough description of a person's condition such that whatever accuracy is lost is made up for by the usefulness of the model. In any case, the model is easy enough to adjust to a comparable configuration such as 35-60-85 or 40-60-80, as long as the saving period is the same as the retirement period and you're comfortable with the life expectancy estimate).

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The question is, in a 30-60-90 scenario, how much do you actually have to save per month or per year  for retirement, given your chosen lifestyle, inflation, and the possibility of earning from investments? To find an answer, let's take look at the situation in another way. The image above shows how your total wealth will behave given the saving and spending pattern described previously. What we can do is rearrange some of the green "blocks" above and invert the right side of the pyramid so that it will look like this:

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In the first image, it seems that the first 100,000 deposit takes 59 years before it is used up, the second 100,000 takes 57 years, and so on, until the 29th 100,000 lasts for three years, and the final 100,000 (the tip of the pyramid) gets used up in one year (the 60th year). If we rearrange the blocks like in the second image, instead of having multiple/different horizons for your deposits, now each 100,000 deposit gets withdrawn after 30 years, and all deposits have the same 30-year horizon.

This is what makes the 30-60-90 tool useful: it assumes that whatever you set aside for retirement in a particular month or year, you withdraw and use 30 years later. And since all deposits to your retirement fund have the same horizon, you just have to compute for one amount that you need to save in a particular month or year.

Estimating retirement expenses

The process starts by estimating your monthly or annual expenses for when you retire but at today's prices. If you want to maintain your current lifestyle, just estimate your personal expenses per month, on average; adjust the amount upward or downward if you prefer a more comfortable or a simpler lifestyle, respectively. Do not adjust for inflation--at least not yet, we'll go to that later. Also, estimate only your personal retirement expenses--not your wife's or whoever else's--unless your wife is a home-maker (i.e., unemployed for life) and do not include discretionary expenses such as your child's college tuition as these will have to be considered separately. The basic components of your estimate should be food, rent/housing, and transportation.

To give you an example, I recently asked a good friend to do this exercise. According to him, he would need 400 pesos per day for food and other daily expenses, and 20,000 per month for rent and car payments, which amounts to 32,000 pesos per month in today's peso.

If we live in a world where prices are constant and investments don't earn returns, using the 30-60-90 framework, my friend has to save 32,000 per month just to meet his retirement expenses given his chosen lifestyle. Seems daunting, doesn't it? What if we consider inflation, and my friend just chooses to tuck away his savings in a bank savings account? Then he'll definitely need to save more than 32,000 per month today. How about if he invests his retirement fund in a "riskier" investment such as an equity UITF, how will this affect his savings goal?

In Part 2 next week, we'll discuss exactly how inflation and investment returns figure into the model. For now, try to estimate your monthly retirement expense in today's peso and see if you can afford to save that amount.

Have a great weekend!