The calculations of life

Do you ever wonder how long you’re going to live? Like, is this the year to buy a new car or not.

Like many people my age, I’ve started paying more attention to the obituaries page in my local newspaper.

It’s not that I’m afraid of dying, although I used to be when I was younger. It’s just that I don’t want to die before my expiry date, or perhaps worse, past it.

No, I’m checking the obits to get a daily update on how long I’ve got left.

A well-known politician died a few days ago; he was two years younger than me. On the other hand, a famous scientist passed on the same day and he was 87.

There’s reassurance in those numbers using a formula I’ve developed. The difference between the scientist at 87 and my age, 70, is plus-17 years. The difference between the politician’s end point and my age is minus-two. So take two away from 17 and divide by two equals 7.5 years. Add 7.5 to 70 gives you 77.5 years, which is my mythical life expectancy gauge for today.

Of course, you could just average the three ages — 68, 70 and 87 — but that that comes to 75. Do you really want to cheat yourself of two-and-a-half years of life?

Why does this matter? Well it doesn’t, of course, unless you’re making long-term decisions.

For example. When I turned 65 my mechanic discovered the floor was rusted out on my old Jeep and I had to buy a new vehicle. In Canada, where I live, the life expectancy of a man my age is about 70 years. However, given my dad lived until he was 91, I figured I was at least good until 75.

(That calculation, should you care, is based on the fact my father was a minister who never smoked or drank alcohol; I, on the other hand, am a journalist who’s done pretty much it all).

Eventually I settled on a Honda Civic, fully loaded. The salesperson assured me it was good for 250,000 kilometers — about 155,000 miles. So at 25,000 kilometers of driving a year, which I estimated I do, that vehicle would safely get me around until I was 75 years ago.

Perfect.

The car is now five years ago. It shows 101,000 kilometers on the odometer, an average of only 20,200 kilometers a year.

Even more perfect. At this rate that car is going to last until I’m 77.5 years ago. And to my way of thinking based on today’s calculation, so am I.

Sometimes, though, these kinds of decisions are more complicated. I went to the dentist recently. She wasn’t happy with what she found in my mouth, a bunch of tiny cavities on the bottom row that need filling and a crown that needs replacing. Total cost, about $2,500, of which health plan will only cover 70 per cent.

How long would that last, I wanted to know. Maybe five years, said the dentist. Alternatively I could get a full set of dentures. They would last for decades. No more cavities for the rest of my life — and then some. But my health plan only covers 50 per cent of what could be a $5,000 bill.

If I’m only going to live to 77.5, clearly fillings offer the best value. But if I’ve calculated wrong and I live to 85 or 91, like my dad, well fillings would be a mistake.

Who said life gets easier as we get older anyway?