Andrew Gelman responds to Rajiv Sethi:
I suspect that within a decade, blogs will be a cornerstone of research in economics. Many original and creative contributions to the discipline will first be communicated to the profession (and the world at large) in the form of blog posts, since the medium allows for material of arbitrary length, depth and complexity. Ideas first expressed in this form will make their way (with suitable attribution) into reading lists, doctoral dissertations and more conventionally refereed academic publications. And blogs will come to play a central role in the process of recruitment, promotion and reward at major research universities. This genie is not going back into its bottle.
And he thinks this is a good thing:In fact, the refereeing process for blog posts is in some respects more rigorous than that for journal articles. Reports are numerous, non-anonymous, public, rapidly and efficiently produced, and collaboratively constructed. It is not obvious to me [Sethi] that this process of evaluation is any less legitimate than that for journal submissions, which rely on feedback from two or three anonymous referees who are themselves invested in the same techniques and research agenda as the author.
I don't disagree with these sentiments, although I do think that, if blogging every becomes important in statistics, it will come much slower than in economics, political science, computer science, or even mathematics. Blogging has been big since 2003... But in all these years, very few statistics blogs have achieved much attention.
Sethi points out that, compared to journal articles, blog entries can be subject to more effective criticism. Beyond his point (about a more diverse range of reviewers), blogging also has the benefit that the discussion can go back and forth. In contrast, the journal reviewing process is very slow, and once an article is published, it typically just sits there. I personally like to publish discussion papers (that is, articles where others discuss and then I write a rejoinder), but most published journal articles don't have that format. (In that way, statistics may be better than economics. The field of statistics appears to accept that articles are attempts rather than realizations of perfection, whereas my impression is the economists worship at the altar of the "home run," the article that is such a perfect jewel that it is beyond criticism.
Can/should the blogosphere replace the journal-sphere in statistics? I dunno. At times I've been able to publish effective statistical reactions in blog form (see, for example, my skepticism about reported statistical significance in a brain-scan study) or to use the blog as a sort of mini-journal to collect different viewpoints (for example, our discussion with Pearl, Dawid, and others on causal inference). And when it comes to pure ridicule (I think you know who I'm thinking of here), maybe blogging is actually more appropriate than formally writing a letter to the editor of a journal.
But I don't know if blogs are the best place for technical discussions. This is true in economics as much as in statistics, but the difference is that many people have argued (perhaps correctly) that econ is already too technical, hence the prominence of blog-based arguments is maybe a move in the right direction. Even technical types such as Paul Krugman and Greg Mankiw have become much more talky and less algebraic as bloggers than as authors of journal articles.
Statistics, though, is different. Setting aside debates about whether Ph.D. students in statistics should learn the strong law of large numbers (I think you can guess my position on that one), even the applied stuff that I do is pretty technical--algebra, calculus, differential equations, infinite series, and the like.
Can this sort of highly-technical material be blogged? Maybe so. Igor Carron does it, and so does Cosma Shalizi--and both of them, in their technical discussions, clearly link the statistical material to larger conceptual questions in scientific inference and applied questions about the world. But this sort of blogging is really hard--much harder, I think, than whatever it takes for an economics professor with time on his or her hands to regularly churn out readable and informative blogs at varying lengths commenting on current events, economic policy, the theories of micro- and macro-economics, and all the rest.
I think few will disagree that the most effective statistics blogging, by a longshot, has been Nate Silver's polling and election analysis on fivethirtyeight.com. Here, Nate and I have actually published a couple of journal articles based on material related to the blog, but (a) the journal articles are quite a bit more technical than the blog entries, and (b) as journal articles, they don't represent major research efforts--rather, they fall into the "fun applications" category. Ultimately, Nate's blogging succeeds because it is news, not because of its research content. From another direction, I think Scott Sumner's econ blogging succeeds because it is well-written and because it supports a fiscally-conservative position that many people want to hear. Krugman's blog works because it's linked to a popular New York Times column and he takes a strongly partisan political stance, and Levitt and Dubner's blog succeeds along the same lines as Cowen and Tabarrok's--readers are getting a mix of news, provocation, and bite-sized analyses. All of these play important roles, but not quite the roles of journal articles.
On the other hand, the current system of scientific journals is, in many ways, a complete joke. The demand for referee reports of submitted articles is out of control, and I don't see Arxiv as a solution, as it has its own cultural biases. I agree with Sethi that some sort of online system has to be better, but I'm guessing that blogs will play more of a facilitating informal discussions rather than replacing the repositories of formal research. I could well be wrong here, though: all I have are my own experiences, I don't have any good general way of thinking about this sort of sociology-of-science issue.