Two years ago, I wrote a column about “blogs” (Web logs) because they were the most interesting new Internet phenomenon I had come across. Essentially, they are personal Web sites that offer people daily (even hourly) commentary on current events or whatever they feel like writing about. Last year at this time, I wrote another column on this topic, so I guess it has become something of a tradition for me. This is my latest discussion of the blog phenomenon.

In my first commentary, I noted that journalists like Andrew Sullivan, Mickey Kaus, and Matt Drudge, as well as publications such as National Review, The American Prospect, and Reason magazine had established blogs. Last year, I noted the growing number of academics who were commenting regularly in this form, including Brad Delong (University of California at Berkeley), Eugene Volokh and Steve Bainbridge (both of UCLA), Glenn Reynolds (University of Tennessee), Steve Antler (Roosevelt University), and Tyler Cowen and Alex Tabarrok of George Mason University.

What I have discovered in the past year is that there is increasing specialization among bloggers, with more staking out narrow areas of commentary. Since my main interests are economics and tax policy, I have singled out a few blogs in these areas that I have found to be valuable resources.

In the tax area, the most prolific blogger is tax professor Paul Caron of the University of Cincinnati. I find him useful because he really keeps on top of the scholarly research among other tax professors. In most cases, this research is available on the Internet in the form of working papers that may be available months or even years before they appear in inaccessible law reviews. This is extremely valuable to me in terms of keeping ahead of the curve on tax research.

Other tax professor bloggers are James Maule of Villanova University and Daniel Shaviro of New York University. They tend to talk more about current tax policy issues from an academic point of view. What I like about both of them is that they are highly opinionated. Neither pulls any punches in saying what they think is stupid about recent or proposed tax legislation. I don’t always agree with them, but they always make me think.

Another tax perspective comes from Kerry Kerstetter, a certified public accountant. His commentary is less academic and more practical. He offers advice on real world tax problems, especially those faced by small businessmen. And he seems to find every cartoon dealing with taxes that appears anywhere.

On economics, I have become a regular reader of the blog jointly produced by George Mason University professors Don Boudreaux and Russell Roberts. They are particularly good on free trade, an area where even some free marketeers have been seduced by the siren song of protectionism. Messrs. Boudreaux and Roberts also do a good job of making technical issues accessible to a general audience.

On international trade, an indispensable blogger is political scientist Daniel Drezner of the University of Chicago. He has been especially outstanding on the so-called outsourcing issue and does an excellent job of staying on top of the research in this area. Unfortunately, despite the fact that every single serious article or paper on this subject has shown it to be a non issue, it continues to excite xenophobes and others who lie awake nights worrying about the trade deficit.

Blogger professor Andrew Samwick of Dartmouth University may become must reading in the coming year because he is an expert on Social Security privatization. Although favorable to the idea in principle, he is skeptical of free-lunch solutions, which could make his commentary particularly timely.

I am right leaning, politically, but I continue to find value in the commentary from friends on the left. The best is Kevin Drum of Washington Monthly magazine. The magazine itself has gone downhill, in my opinion, having become more doctrinaire and less iconoclastic since the retirement of its founder, Charlie Peters. But Mr. Drum remains sufficiently independent to keep me reading.

Another lefty Web site that I read regularly is someone known only as “Angry Bear.” I don’t know who he is, but he offers sophisticated commentary by an economist with a left-wing perspective. He is very good at poking holes in weak conservative arguments for policies that I support, helping me strengthen those arguments and help get them enacted.

One disappointment this year in the blog area has been the weakness of some institutional blogs, those sponsored by newspapers and think tanks. They are often unreadable and seldom linked to. It confirms my view that blogs are necessarily idiosyncratic and need to be pretty independent in order to be successful.

I believe that the Internet has barely scratched the surface in using blogs to analyze and disseminate information. I look forward to their continued evolution.

Mr. Bartlett is a senior fellow at the National Center for Policy Analysis.