Drug Hoarding and 'Prisoner's Dilemma'

Oct. 24 -- Dilemmas often arise when people feel vulnerable. A case in point is the situation regarding the drug Ciprofloxacin, which some are stockpiling more to combat anxiety than to ward off anthrax.

The benefit of these purchases is a feeling of greater personal security, but one social cost is that Cipro may be in short supply if and when it's needed in large quantities. Another social cost is the increased bacterial resistance to the antibiotic that is likely to result from its widespread use.

The Prisoner's Dilemma

The so-called prisoner's dilemma is often used to model such conflicts. The dilemma owes its name to the scenario wherein two men suspected of a burglary are arrested in the course of committing some minor offense. They're separated and interrogated, and each is given the choice of confessing to the burglary and implicating his partner, or remaining silent.

If they both remain silent, they'll each receive only one year in prison. If one confesses and the other doesn't, the one who confesses will be rewarded by being let go, while the other one will receive a five-year term. If they both confess, they can both expect to spend three years in prison. The cooperative option is thus to remain silent, while the individualist option is to confess.

The dilemma is that what's best for them as a pair, to remain silent and spend a year in prison, leaves each of them open to the worst possibility, being a patsy and spending five years in prison. As a result they'll probably both confess and both spend three years in prison.

The Impact of Many Small Decisions

Most of us aren't crime suspects, but the dilemma provides the logical skeleton for many situations we do face everyday in real life. Whether we're competitors conducting business, spouses negotiating understandings, or anxious citizens vying for antibiotics, our choices can often be phrased in terms of the prisoner's dilemma. The two parties involved will often be better off as a pair if each resists the temptation to go it alone and instead cooperates with or remains loyal to the other person. Both parties' pursuing their own interests exclusively leads to a worse outcome than does cooperation.