If There’s a Growing Epidemic in Depression, How Come the Happiness Data Don’t Show It?

[Cross-posted to Happiness and Public Policy]

An email exchange with Virginia Postrel prompted me to note for the first time that there's a real problem in trying to use the happiness data and the depression data at the same time. Almost all the “paradox of prosperity” books cite happiness data that is supposed to show that we're not getting much, if any, happier as we grow wealthier as a society. Alongside, they cite data purporting to show that depression is approaching epidemic proportions. But the happiness and the depression data contradict each other. You can't in good conscience appeal to both.

The “paradox” books generally show a graph illustrating the stability of the percentage of people reporting that they are “very happy.” But they could also show a similar graph of the stability of people reporting that they are “not too happy” or “not at all happy” (depending on the survey). For example, Branchflower and Oswald, “Well-Being Over Time in Britain and the USA,” show that, in the US, the number of folks reporting that they are “not too happy” (on the three option surveu) dropped from 14% in the 1972-1976 period to 12% in the 1994-1998 period (which is up from the 1988-1993 low of 10%). Similarly, in Britain, the number reporting “not at all” and “not very” (on the four option survey) was 4% and 11% respectively in the 1972-1976 period, and 3% and 10% in the 1994-1998 period.

If depression rates have been rising stratospherically, how come the happiness surveys don't track this fact at all, but instead show a small decline in the number of dissastified people? On its face, it looks like the happiness data contradicts the depression data. Indeed, the happiness data would seem to support the Horwitz-Wakefield hypothesis that the apparent increase in depression is almost entirely a function of the flaccidity of the diagnostic category.

One way of addressing the apparent contradiction, suggested by Virginia in her review of Gregg Easterbrook's The Progress Paradox, is to point out that depression and unhappiness are very different things. Virginia points to Julian Simon as an example of a happy person who stuggled with depression. It is indeed plausible that some genuinely depressed people, for whom life is otherwise going very well, will experience their depression as an external malady–an alien force unprompted by events–and so will nevertheless report that they are happy.

However, it seems at least as likely that the depression will cast a shadow over life, and negatively effect one's assessment of how well things are going. Indeed, it is not at all uncommon for depression to cause major problems in precisely those areas most important for the sense that one's life is going well, such as work and love. So, if there was in fact a huge increase in depression, we should expect at least a significant fraction of those people to show up in the lowest category of self-reported happiness, even if many others are reporting that they are happy despite their depression.

Additionally, if an increasing number of people are simply functionally sad, as opposed to pathologically depressed, due to a death in the family, a bad break-up, or a lost job, you'd think that they'd show up in the happiness data. This is preciesly the sort of thing the happiness data is supposed to be measuring. It does, in fact, pick up the negative hedonic effects of higher unemployment rates, for example. There simply is no increase in subjective ill-being, as measured by the surveys.

Therefore, if you're going to use the happiness data to show that we're not getting happier as incomes rise, you can't turn around and use dramatic depression data that, if accurate, ought to show up pretty dramatically in happiness data that, on the contrary, suggests a mild decline in the percentage of the depressed and sad. At the very least, you need some explanation of why this profound epidemic of depressive mental illness has, amazingly, absolutely no effect on the data from which you are drawing most of your conclusions.

I'm sort of amazed that this didn't occur to me earlier. And I'm really amazed by the fact that the apparent inconsistency just doesn't come up (I don't think) in the “paradox” books. When you think about it, if there was really a widening plague of depression AND average happiness was stable, then you'd need need a growing cadre of really happy people to offset the growing legions of the depressed. But all the books make a show out of the fact that there isn't a growing cadre of really happy people, and they all admit the average is stable. So you'd think the “rising depression” idea would raise a red flag or two.

I think it's pretty clear that the depression data is junk. And that's trouble for the “paradox” genre. If you're unable to honestly say that we're getting more miserable, you're left with data that show that we're slightly better off and no worse off than we've ever been, since we've been measuring this sort of thing, at least. And here's a pretty hard argument to sell: We're happy as ever. Therefore, radical interventions are required!

[Cross-posted to Happiness and Public Policy. Please leave comments there.]