Blogging vs. long-term research?

Virginia Postrel and Andrew Sullivan ask whether blogging interferes with one’s long-term projects and commitments, such as writing books.

For me it has been simple.  I’ve always tended to work on too many topics and questions in the first place.  Daily blogging satisfies my intellectual "Wanderlust" very well.  This makes it easy to concentrate on more specialized research, namely my main field of economics and culture.  Since I’ve started blogging my research has become more focused, which is overall a good thing.  In other words, the portfolio effect has outweighed the substitution effect.