Do Critics Matter?

I was all set to attend what sounded like a great discussion on "The Dumbing Down of American Culture: Fact or Fiction?," featuring our own Michael Hirschorn (he of "The Case for Reality TV") - but then it was cancelled. So as a poor substitute, I'll offer a link to this Slate piece, in which Erik Lundegaard argues that once you control for marketing budgets and theater saturation (big things to control for, obviously), well-reviewed movies tend to outgross their badly-reviewed competitors. Lundegaard goes on to suggest that this proves that "quality matters," and that this means in turn that movie critics matter as well. I'd like to think so, and I'm sure they matter on the margins - I know I've avoided films I was intending to see because a critic I respected panned them - but in the aggregate I think his model is slightly flawed: He looks at the relationship between good reviews and good box office across a movie's entire run, a period in which word-of-mouth presumably becomes a big factor in how the movie performs. On the assumption that what your friend tells you about a given film may matter way more than what a critic tells you, I'd like to see the same analysis re-run but confined entirely to opening weekends, when word-of-mouth presumably is close to a non-factor, and when the critics are a moviegoer's only guide to which films are worth seeing and which can be safely skipped.