The Economist has an astonishing track record of success and in an interview on mediabistro.com the magazine's Matthew Bishop (New York Bureau Chief) gives some insight into how it works. For example, on the no-byline policy:
Because we don't have our name on the article, we all stand and fall by all of the content.
This changes completely the internal dynamics. When you think about the extent to which debate is what we do, the other part of that is that we all stand together as a collective as to all the material that appears. Which means we are much more consistently high quality. Having this group of people here, and having this long record of debating, means we see things going on differently then our competitors. It's not just one individual, it's a group narrative. If you put bylines on it, it will make much harder to maintain that.