I introduced another change for the PC meeting for STOC this year. My experience is that theory conferences are somewhat "loose" about conflicts of interest. What I mean is that while PC members can't submit papers, and it's expected that you don't review papers of current (or recent) students/advisors, other than that conflicts of interest aren't usually treated as a big deal. As a contrast, it's standard for the networking PCs I've been on to be at least as rigorous as an NSF panel; for example, if a paper has ANYONE at your institution as an author, you have no electronic access to the reviews and you're expected to leave the room during the discussion (and similarly for other "standard" conflicts of interest, including any collaborators from say the last two years). In my experience, on theory PCs, people don't leave the room just because they have a conflict. It might be expected they'd not comment, although it's not always clear to me this expectation is followed.
Indeed, I remember my first SIGCOMM PC -- the first hour or two I kept wondering why people kept coming and going in and out of the room every time a new paper was discussed. It seemed like a lot of people were off to get coffee when they weren't a reviewer on the paper. Someone explained to me that these were the people with conflicts, and I was shocked at what was considered a conflict. (I figure anyone from UCSD or Microsoft currently has to leave the room for at least 1/4 of the papers on any networking PC.)
Interestingly, when I mention this difference in "style" to people, networking people seemed shocked (and maybe a little horrified) by how theory PCs handle conflicts, and theory people seem shocked by how networking PCs handle conflicts.
[Aside: it's a bit interesting to think about further this in light of the comments on my previous post on sending scores, where many people note that many authors can get "inside information" on their paper from PC members after the fact, even though the meeting is supposed to be "confidential". This post won't cover that further -- it was actually written before the other post!]
It's a bit hard to imagine utilizing such a strict conflict of interest polity for a theory PC. The community's a bit smaller, we're highly collaborative, and the papers can be so specialized that if you stick hard and fast to conflict rules you might not have enough PC members who are really suitable to judge a specific paper. Another negative is that it does cost time -- there's a switching cost when people enter and leave the room.
But I asked the PC for a straw vote, and a large majority of those with an opinion thought it was a good idea to have people with conflicts of interest leave the room, primarily for the obvious reason that it's a lot easier to have an open discussion when you're not worried what some people might hear. (Not surprisingly, younger PC members on average seemed to think this was a bigger concern.) I should be clear, however, that this idea was quite controversial; many PC members expressed a very clear and vocal dislike for a policy that had people leaving the room regularly. Indeed, it was definitely the most controversial decision I made as the PC chair.
In order to be practical, I made it clear that I understood there would have to be exceptions, as needed, to deal with special cases, since I didn't really plan for this policy from the beginning (including when making paper assignments, although I did ask PC members to mark conflicts with the software when ranking papers they wanted -- this did not seem to be treated uniformly and universally by the PC, again because it's probably not standard in theory conferences). But the policy I planned to implement was essentially the following: if you had any standard conflict on a paper, and there wasn't a very good overriding reason for you to be in the room (e.g, you were an original reviewer, or you had a specific expertise the committee needed to evaluate the paper), you should leave.
In the next post, I'll talk about how that worked.
But before that, I think this is a matter the community (or, to the point, conference steering committees) should address. My personal take over many, many PCs is that while the strict conflict interpretation used in networking conferences may not be completely workable for a STOC/FOCS type conference, if I had to choose, it's clearly better than the "We'll assume everybody will behave properly" approach taken at most theory conferences. (Many theory conferences take a strict line on PC members not submitting, but then do essentially nothing about other possible conflicts -- that just doesn't seem right.) I think something in between these two extremes are possible, where exceptions based on needed expertise is possible, and that's what I tried to implement, but it could use some more careful thinking through. What do you all think?