Always Scribble, Scribble, Scribble! Eh, Mr. Gibbon?
I'm late joining the back-and-forth between Ezra Klein and Jason Zengerle - continued here and here and here, with Matt chiming in here - on whether there's anything like merit pay for journalists, but here's my two cents. I basically agree with Ezra that print journalists' salaries tend to be determined "through some undefined mixture of our editors liking our work and our office presence, the time we've been at the magazine, our age, and so forth," and that this doesn't bear much of a resemblance to a system that pays teachers based on their students' test scores, which is the sort of "merit pay" that kicked off the whole discussion. Jason's right that some media institutions, the Atlantic included, make an effort to figure out who's reading what in the magazine and filter that information into staffing decisions, but I don't think I'm giving away any trade secrets when I say that this remains a highly inexact science, and one that plays a pretty small role in how much everyone gets paid.
However, one factor that Ezra leaves out is output, and especially freelance work, which for many journalists is either a major source of supplementary income or their only source of income, and which follows a somewhat stricter, easily-defined metric than salaries at the Prospect or the Atlantic: The more words you write, the more you get paid. It's not exact by any means, since a freelancer who writes 10,000 words for Esquire and GQ over the course of a year will make more money than one who writes 20,000 words for the assortment of Beltway political magazines, but it's a place, and a pretty important one, where the statistical correlation between performance (measured by words produced) and pay is somewhat more direct.
And then there's the blogosphere, where we do know (roughly) who reads what, and how well individual writers are doing in attracting readers. At least a few prominent bloggers already have deals with their publications whereby they're paid more for higher traffic, and less for lower traffic, and of course if you run your own blog, your blog-ad revenue is determined by how many readers you attract. So as journalism becomes less print-bound and more bloggy, Ezra's claim that journalists don't get paid for performance, of some kind at least, will be less valid than it today. Whether it's the sort of performance that makes for high-quality journalism is another question entirely.