The Logic of Life

An excerpt from a book I’m reading (The Logic of Life) on how taking drugs (or smoking) can be rational, according to Tim Harford, the author:

It can also be rational to get hooked in the first place. Imagine a young man who is thinking of trying a new drug. He knows that everybody who tries it loves it, at least at first. Then some users find their lives degenerate into an increasingly desperate and futile attempt to recapture that initial buzz, leading to the pain of cold turkey or the anguish of eternal, unfulfilling addiction. Others seem able to enjoy the highs and remain quite content for the rest of their lives. He has no way of knowing into which category he will fall. Is it rational for him to ingest the drug?

If you say ‘no’, read the paragraph above again but replace ‘trying a new drug’ with ‘getting married’ and ‘cold turkey’ with ‘divorce’. Getting married is not so different from getting hooked. It might not work out, it will restrict your future freedom of choice, and quitting if things turn sour is going to be extremely difficult and painful. but it will probably be a lot of fun, too. The first-time drug user (or the newlywed) might be making a mistake, but he or she thinks that on balance the decision will pay off. That, according to Becker and Murphy, is what addicts do.

Another excerpt; this one is on how some addicts (drinking, smoking, etc.), in light of a price increase of cigarettes or booze, might prefer to kick the habit by going cold turkey (in other words, by stopping entirely), rather than doing it by constantly reducing consumption (bit by bit) over a period of time:

Becker and Murphy also predict that because addiction is self-reinforcing, with each fix creating a greater desire for the next fix, cold turkey is the rational way to quit. The surprising implication is that addictive goods can be more sensitive to price changes than non-addictive goods, and addicts may pay more attention to price than light users do. The light users can cut back if prices rise, while the heavy users might prefer to stop entirely. It sounds ridiculous, but turns out to be true: when liquor taxes are raised, the consumption of alcohol falls but the death rate from liver cirrhosis falls more sharply. In other words, when the prices of booze increases, alcoholics are the ones who cut down most on their drinking.

But like all things, one can never be “purely rational or purely irrational”.