I Will Live to Be 87

While I can't speak for the construction of Northwestern Mutual's web applet, I can tell you the actuaries who guide its underwriting do attempt to project out future changes in general life expectancy. But the certainty that you have that the trend is a positive one isn't necessarily consensus. Median life expectancy in the U.S. grew by leaps and bounds between about 1955 and 1980 -- gaining almost 15 years. It has crawled. The gains have been much more modest in the last quarter century -- less than five years. And given the explosion of obesity, there are some who predict the general trend over the quarter century will be downward.

I think this applet is totally PC. Not only do they not ask income, but also they don't ask race.

Well, looks like I'm falling a little shørt. Time to start exercising. :-)

Evidently, I'll live to be 92.

Some of the factors have a correlation that goes with income. For example, fruit & vegetable consumption.

Here, as is often observed, the least expensive foods in grocery stores tends to be the stuff that's really bad for one's health. Fruits and vegetables however, tend to be more expensive than these foods.

For people at the low end of the income spectrum, it's not uncommon for the less healthy foods to substitute for the healthier, but more expensive foods in their diets. So we would seem to have an income-related factor, to some degree dressed up as something else.

Would anyone care to speculate which factors might serve as a proxy for race?

I think income has a lot to do with life expectancy. The more money you make the protected you are so speak. The less you make the more you are exposed to an unsafe environment. This in my eyes has alot to do with how long you live' but im just speaking from my own personal experiences.

You can play around with the answers a bit to see what the effects of various choices are. Most of them are fairly subtle, except for the last one. That question asks if you use 'drugs for "recreation"' (quote marks theirs). The applet cuts a whopping 9 years off your life if you do, but it displays a pretty picture of a blunt with a big red line through it if you don't.

It's hard for me to evaluate whether 9 years is reasonable in this case. I'm unaware of any research showing that marijuana (by far the most commonly used illegal substance) cuts life expectancy at all, let alone 9 years. If I were sure that they were just talking about pot, I would say they are probably just wrong.

But of course, the good people at Northwestern Mutual display their pretty picture of a blunt together with a little text referring to "hard drugs like cocaine and narcotics," which are commonly lumped into the same bucket. As far as I am aware, cocaine can indeed cause cardiovascular problems, whereas "narcotics" (I suppose they mean opiates) have little direct effect on lifespan except by way of the risk of overdose -- a risk that can be considerable if one purchases one's fix on the streets.

Moreover, the actuaries might be trying to use "drug use" as a proxy for a generally high-risk lifestyle and disregard for the law. That could make perfect sense from an insurance company's point of view, even if it shows nothing about the actual effects of any illegal substance.

Actuaries (disclosure: I'm one) do include mortality improvement in their tables, and when we calculate life expectancy, we do take into consideration that you've survived to your present age.

There's all sorts of underwriting variables we could use. Race is not particularly well-defined (and besides, we're not allowed to use it for commercial products), but I'm sure many other variables, such as hypertension and diabetes and family history of heart disease, are correlated with the heightened mortality one sees in various races. Also, there are mortality differences by occupation, though that's also correlated with things such as education and hobbies/habits (for example, you see lots of construction workers taking smoke breaks... not so many yoga trainers).

Anyway, you can slice it many ways.

Also, I just did it for my variables, and the result looks about correct (I play with life tables all the time). I don't know how they're doing the applet - I'm going to guess they're using Cox proportional hazards models, where each item has a certain %age effect on mortality.

Since genetics is by far the greatest determinant, and is commonly only shortened by behavioral factors, I daresay most people can form better judgments on their own.

Question: Are the thrifty longer lived and spendthrifts shorter lived? Is their propensity to spend related to their lifespan?

(Perhaps a little, but not much, I believe.)