Co-blogger Eugene Volokh gives some sensible reasons for why he chooses not to blog about some topics. I gave my own criteria for making such decisions here:
I try to limit blogging to issues where I have a comparative advantage: that is, questions on which I can say something useful or interesting that is unlikely to be said by others…..
I take seriously the implications of some of my own scholarly work on political ignorance. Merely knowing a few basic facts that can be gleaned from perusing a newspaper is not enough knowledge to conclude that I have something original and important to say about an issue, except in very rare cases where the issue in question is unusually simple. My experience as an expert on political information is that there are far more issues that are more complex than most nonexperts believe than the reverse….
For these reasons, I try to limit my posts on political issues to the following three categories:
1. Issues on which I am an expert (primarily political participation, federalism, and property rights). This is where I have the greatest chance of making an original contribution.
2. Issues on which I’m not officially an expert, but have a lot of knowledge because I follow them closely (i.e. – far more closely than merely reading occasional articles about them in the media or online).
3. Rare cases that fall outside of 1 and 2, where I come up with an original point that other commentators have for some reason ignored.
Have I violated these principles in the four years since I first developed them? Probably. There surely have been situations where I thought that some issue fell under category 2 or 3 when it really didn’t. Even experts on ignorance sometimes overrate their knowledge! But the fact that I don’t follow my own rules perfectly doesn’t mean they aren’t good rules. The quality of political debate would be improved if more pundits stuck to issues where they know what they are talking about.
Many people (including, perhaps, a few of our readers) tend to assume that if you are a lawyer or a law professor, that must mean you are an expert on every possible legal issue. In reality, that simply isn’t true. There is far too much law out there for anyone to be an expert on more than a small fraction of it. Even within a particular subfield, it’s hard to be an expert on every part of it. For example, I teach constitutional law. But that doesn’t make me an expert on every constitutional issue out there. I know a lot about federalism and property rights, the issues I write about the most. I also have considerable (though lesser) knowledge of several other constitutional issues. On the other hand, there are areas of constitutional law (e.g. – the criminal law provisions) that I know very little about.
I try to be aware of the limits of my expertise, and so should my readers. If you want to read about a subject that I don’t know much about, you are better off looking up the works of someone who is a real expert in the field rather than asking me to write about it.