I’ve written elsewhere (here and here) about specific instances where poorly created law can result in undesirable consequences. I attempt now to address the core issue that causes these specific instances to occur.
I’ve written before that Law is our attempt to make Morality and Economics coincide. The key thing is, how do we go about properly constructing laws? To do this, we need to understand the distinction between ends and means.
Any incentive system incents a particular behavior. The thing that it incents is the end. Unless specifically prescribed or proscribed, nothing is said about the means used to acheive that end. This is a universal truth. However, when the thing incented is really just the means to some other end, the connection between the original end and the newly defined end can be lost. When this happens, it is possible to follow the letter of the law while missing the spirit of it.
The problem with some laws is that they they confuse means and ends. This isn’t unusual. Many people don’t know how to analyze a problem to determine what the real problem is. In my essay on Smoking Bans, I pointed out how the goal is to improve public health by prevent diseases caused by second hand smoke inhalation. Instead of properly articulating and remaining focused on this key issue, various lawmakers instead wrote law that allowed for only one kind of solution. In my essay on Child Pornography, I pointed out how legislators lost sight of the goal - stopping the distribution of child pornography - and instead focused on one particular process that might help stop it. The failure here is that the chosen solutions may not acheive the desired results, and could have undesirable side effects, which, given the slow pace of change in the law, can result in needless suffering.
While focusing on the ends is critical, that is not to say that we should never have laws that deal with means. As stated previously, the state has an interest in encouraging childrearing. Even though there is a strong interest here, we don’t allow children to be raised to be slaves, nor do we allow incest as a means of procreation. Why is that? It is because we recognize that the side effects of some things are in and of themselves undesireable, even if we can’t properly or completely articulate what they all are. Given the complexities of human behavior, it can be difficult to fully describe an end that properly delineates which means are allowed and which aren’t - we humans are very creative in finding ways to push the envelope. For practical considerations, it is often simpler to proscribe swaths of behavior than attempt to articulate all the ill effects they engender.
Having said that, we shouldn’t lose sight of why we do this - we proscribe means because of a multitude of unarticulated ends. The goal should always remain to focus on the ends that matter, avoiding addressing means if at all possible. This will keep the law flexible and resilient - and able to keep up with changing times.