Forbidden Fruit: When Prohibition Increases the Harm It Is Supposed to Reduce.

• Author: FILLEY, DWIGHT

Various activities, such as drinking alcohol, smoking tobacco, and using psychoactive drugs, have been prohibited by governments at various times. Ostensible motives for the prohibitions have included helping people to lead "good" lives (in the opinion of the lawmakers) by keeping them from temptation, and preventing behavior that harms society as a whole. Evidently lawmakers have assumed that if they prohibit an activity deemed harmful, then the harm individuals do to themselves and to society will decrease--corruption aside, why else would they impose such prohibitions? Let us examine the evidence for their assumption. If it is incorrect, if indeed prohibiting an activity causes it to increase rather than decrease, then the whole prohibitionist program is called into serious question.

My thesis is that because reducing only the harmful types or aspects of certain behaviors is difficult, governments often resort to prohibiting all types or aspects of the behavior, both the harmful and the benign. Such flat prohibition often leads to an increase, rather than a decrease, of the harmful behavior.

In reviewing the literature on the effects of such laws, one repeatedly sees a curious pattern. Although conventional wisdom presumes that a prohibitory law will have the desired effect and lawmakers act in accordance with such "wisdom," careful studies of the operation of the laws often show the opposite effect: the behavior they are supposed to inhibit actually increases.

It is beyond the scope of this article to determine exactly why that seemingly strange reaction sometimes occurs. But even a little imagination suffices to suggest some possible reasons. Some people simply enjoy doing what is forbidden, for the thrill of breaking the rules. Others may resent being told what to do, preferring to be asked or persuaded. People may resent living under laws that restrict nonabusers in an attempt to constrain the abusers, so the intrinsic injustice of blanket prohibitions may prompt perverse reactions. Finally, when scarce police and court resources are diverted toward the prevention of the nonabusive forms of behavior, fewer resources remain to be used in preventing the abusive behavior.

There is ample evidence that arresting, convicting, and punishing wrongdoers who harm others reduces such harmful behavior. However, as I will show, prohibiting all related behavior in an attempt to reduce the harmful portion is far more problematic, and often is counterproductive. If prohibitory laws have the opposite of the intended effect, that outcome has profound ramifications for policy makers. Let us consider some cases.

Prohibiting Teen Smoking

There has been a long history of attempts to prohibit cigarette smoking. All such attempts have failed.

Washington, North Dakota, Iowa, and Tennessee banned the sale of cigarettes in the 1890s, but the laws were generally ignored (Dillow 1981, 94-107). Although good data apparently do not exist, some evidence indicates that cigarette use declined between 1896 and 1901 but then increased continuously until the prohibitions were repealed between 1911 and 1922 (104). Cigarette sales continued to climb in the United States until 1965 (Statistical Abstract 1971, 701; 1996, 700). Thus, if the limited available data are correct, the prohibited activity increased during the period of prohibition and continued to increase after prohibition was repealed.

After World War II, cigarettes were in extremely short supply in Germany because of rationing and the generally disordered economic conditions. That de facto prohibition of smoking gave the Germans a sense of how de jure cigarette prohibition would operate. The episode was recalled during a debate on cigarette prohibition in the German Parliament in 1974, where the conclusion was:

To outlaw production and trade would not turn smokers into non-smokers. It would, on the contrary, create a situation much like the one after the last war, when--in spite of the shortages--the number of smokers increased. There would certainly develop a black market, and the use of all sorts of ersatz substances would only raise the risks to the health of the users. Prohibition, therefore, is no solution. (Hess 1996, 55) More recently, the focus in the United States has shifted to warnings, restrictions, and high taxes rather than prohibition. The decline in cigarette use in the United States since 1965, noted earlier, may point to a more effective alternative to prohibition in reducing harmful behavior.

A notable exception to the abandonment of prohibition of cigarettes has been the prohibition of the sale of cigarettes to minors. The conventional wisdom, of course, holds that such prohibition will reduce teen smoking. All fifty states prohibit cigarette sales to minors, but a study reported in the New England Journal of Medicine (Rigotti and others 1997) finds that such laws are rarely enforced.

To determine whether stronger enforcement efforts would reduce teen smoking, the researchers compared six Massachusetts towns, three with increased enforcement measures and three as controls. They concluded, "The rate of current tobacco use [among teens] rose in the intervention communities but remained stable in controls, the reverse of what would have been expected; however this difference was of borderline significance (P = .05)" (Rigotti and others 1997, 1048). The researchers speculate that teens found it easy to find vendors willing to sell to them in spite of the increased enforcement, and that teens found it easy to get cigarettes from adults or to buy them in neighboring towns where enforcement was not so strict. Vending machines offered another obvious source.

Two previous studies (Jason, Anes, and Birkhead 1991; DiFranza, Carlson, and Caisse 1992) did find that teenage smoking diminished when enforcement compliance reached 90 percent (that is, when 90 percent of minors' attempts to purchase tobacco failed). However, those studies failed to employ controls. As it...