Mark D. White

A recent issue of Science (October 5, 2012) is a special issue on depression, and senior editor Peter Stern's introduction lays out the reason for it (emphasis mine):

Depression is a devastating disease. It affects not only the directly afflicted but also the people around them, their families, and their closest relations. It indiscriminately hits all strata of society, no matter one’s intellectual background, age group, or economic situation. There are many cases of highly successful and widely admired individuals who have been struggling with depression for years. Unfortunately, for reasons we still do not fully understand, this condition has been on the rise over the past decades. Considering its impact on an individual’s quality of life and subsequently on the economy and society in general, gaining an understanding of what causes depression and trying to develop effective therapies is of utmost importance. Hence, this year’s Neuroscience Special Issue is devoted to different aspects of depression.

I've long wondered why economists don't look more at both the microeconomic and macroeconomic effects of clinical depression. (I'm careful to add the modifier "clinical" because economists do, of course, spend a lot of time thinking about depressions, Great or otherwise.) Behavioral economists identify, quantify, and model the cognitive biases and dysfunctions that affect the choices of the average person, but have not yet (to my knowledge) looked into how depression affects decision-making. As Dr. Stern recognizes, choices affected by depression--given reported high rates of incidence of the disease--have potentially tremendous economic effects, not only on personal well-being but also on market outcomes, aggregate economic performance, and government policy.

There are many theories of depression in psychology, but one that seems extraordinarily well-suited to incorporating the effects of depression into economic models of choice is cognitive psychology, as typified by the work of Aaron Beck. Beck maintains “the individual’s problems are derived largely from certain distortions of reality based on erroneous premises and assumptions” (Cognitive Therapy and the Emotional Disorders, p. 3). Examples of this negative thinking include: dichotomous reasoning (everything is either black or white, failure or success), selective abstraction (focusing on failures and glossing over successes), and overgeneralization (exaggerating the importance and incidence of failures). In economic terms, these have obvious effects on beliefs and preferences, the foundation of decisions in the mainstream model of choice.

Depressives also report a lack of motivation or "paralysis of the will" that makes them less likely to act decisively to further their goals. In the mainstream economic model of choice, this can be be regarded once again as a result of distorted perceived benefits and costs (downplaying the former and emphasizing the latter) which result in a bias toward inaction (or at least decisional inertia).

This is just one possible framework, and there are many others. I believe that behavioral economists could work within such a framework to refine the cognitive and conative effects of depression on decision-making. Behavioral economists have already told us that we're "presumably irrational"--now it's time to turn to the members of society who are "presumably depressed."