Blogging's conversational informality

Some of Paul Krugman's blog readers take issue with his informality. He explains that it's important to keep blogging (particularly in his field, economics) from becoming too dry:

You see, the things I write about are very important; they affect lives and the destiny of nations. But despite that, economics can all too easily become dry and boring; it’s just the nature of the subject. And I have to find, every time I write, a way to get past that problem. More broadly, the inherent stuffiness of the subject demands, almost as compensation, as conversational a tone as I can manage.

It would be foolish to apply this point of view to just economics; blogging, in general, requires and deserves an entirely different form and style. We cannot approach the composition of a blog post – often one among many – as we would an essay, for example. The medium lends itself to another kind of writing: one that is conversational, largely unedited, and a little rough around the edges. Colloquialisms can be tolerated, bad spelling and grammar cannot.

We mustn't too-closely associate conversational writing with informal writing. One can write in a conversational style and simultaneously appear verbose and wordy. But, after all, everyone has their own writing style. But economics, I would have thought, would never lend itself all that well to blogging.