Why, Peter Suderman wonders, are music reviews so often positive, while film reviews seem to be equally split between hosannas and hatchet jobs? Peter suggests it has to do with the different cultures that have grown up around movie and music reviewing—which in one sense almost has to be true as a proximate explanation, but for that very reason doesn’t count as much of an explanation. Rather, it defers the question: Why are the cultures different? It can’t just be a question of historical path dependence. Suderman cites the formative influence of folks ike Roger Ebert and Pauline Kael, but they’re pikers in the poison pen game next to the likes of Lester Bangs or Robert Christgau.

I think Tyler Cowen gets nearer the mark with the suggestion that movie reviews are more geared toward helping readers decide what to see, while music reviews are catering to an audience already heavily subdivided by genre and subgenre tastes. He’s also probably right to expect that reviews will trend more positive as a function of cultural fragmentation.

What Tyler doesn’t say outright—maybe because he assumes it’s obvious—is that there’s an basic difference in the economics of film and music that’s driving all this. To wit: Movies are a lot more expensive to make than records, and so you see a whole lot fewer of them, aimed at a relatively broad audience, and backed by mass-media marketing campaigns.

So the movie reviewer is facing a small pool of films you’ve probably heard about already, then basically rating all of them so you can decide which of the ones you may have been thinking of are worth your while.

The music reviewer, by contrast, is going to be able to consume a lot more albums, at least at a first pass, than a movie reviewer can, but can only actually write up a tiny fraction of the enormous output, even within a fairly circumscribed niche. And the music review reader is much less likely to come to the review knowing much about given album, again because albums aren’t as heavily advertised, and because of the sheer quantity of them.

Given the underlying dynamics, it’s no surprise that the distribution of positive and negative reviews looks different, because the two types of reviews are serving different functions. And in a way, I think it’s almost the reverse of what Tyler lays out: Someone reading a movie review is probably moderately interested in the specific film already, based on trailers or ads or buzz, and wants to know whether it’s worth taking the plunge. Someone reading a music review may be interested in the broad genre (or set of genres) covered by, say, Pitchfork—but is mostly looking to be alerted to something novel.  And there’s another sort of symmetry here: The moviegoer has probably seen a promising clip, and consults the review to see whether the movie is likely to deliver on that promise. The album shopper wants the universe of freely available music clips narrowed down—once that’s done, he can make the decision to buy based on his own listening experience.