The news that New York Yankees star Alex Rodriguez tested positive for anabolic steroid use in 2003 should come as no surprise to anyone who knows something about elite-level athletics. (Rodriguez has since admitted to using steroids between 2001 and 2003. He claims not to have used them since.)

Elite athletes are extremely driven, competitive people, who are inclined to do anything that will help them succeed at their sport. Furthermore the economic structure of many professional sports, in which a handful of competitors make staggering sums - Rodriguez has earned nearly $200 million - while 99.9 percent make little or nothing, guarantees that the invisible hand of the market is going to be pushing a lot of banned substances, if they provide any sort of competitive edge (which plenty of performance-enhancing drugs certainly do).

These factors ensure that trying to eliminate performance enhancing drug use in sports will always be somewhat of a losing battle. But is it still a battle worth fighting? Any answer needs to account for the complexity of the issues, which involve health concerns, privacy and the practical limits of what drug testing and enforcement policies can accomplish.

As for health, the most compelling reason for banning performance-enhancing drugs is that they might endanger the health of the athletes who use them. This creates a classic collective action problem: What would be best for athletes collectively is no PED use by anyone, but, given the imperfections of any testing regime, what's best for the individual may well be to get the edge PEDs provide.

Without a sufficiently effective testing and enforcement regime, athletes are to some extent forced by the market to choose between their health and their careers.

But it's not quite that simple. First, the health risks of PED use, like the health risks supposedly posed by most banned or heavily regulated drugs, may be greatly exaggerated. Because of our constant moral panic over drug use, we simply don't have good data on whether, for example, an athlete who used anabolic steroids under competent medical supervision would be running serious health risks.

In addition, it's odd that we become so concerned about the health of athletes when they use PEDs, given that we tend to be rather indifferent to their health in general. Consider that playing in the NFL appears to reduce life expectancy by as much as 15 years, and that it often has devastating health effects on former players even without regard to whether they die sooner.

But hardly anyone seems to be troubled by the fact that simply playing professional football is probably far worse for one's health than even the most unregulated and haphazard PED use.

Then there is the matter of privacy. It never ceases to amaze me how blase supposedly liberty-loving Americans have become about workplace rules which can force a person to urinate into a cup in the presence of a witness for the benefit of the employer's drug-testing policies.

It is, to say the least, unclear whether these sorts of indignities should be endured by professional athletes for the sake of keeping their sports "pure." That's one reason athletes - not to mention other workers - need strong unions, so they can decide for themselves whether they're willing to sacrifice privacy in exchange for the benefits, such as they are, of drug-use regulation.

Finally, whether it's worth implementing any particular testing and enforcement regime has to take into account that the scheme is going to fail to some extent. Given the endless inventiveness of the human mind, the drug users will always be at least half a step ahead of the drug testers.

There may, in other words, be situations where doing literally nothing about PED use may be the least bad solution for the athletes in a particular sport.

Paul Campos is a professor of law at the University of Colorado. He can be reached at paul.campos@colorado.edu.