May 07, 2009
Content to contribute: Wikipedia
From time to time I find pages in my areas of professional knowledge that seriously need improvement. On my long to-do list, editing Wikipedia never seems to make it to the top. But I might as well start a list in case I am looking for something to do in the future, or better yet, to suggest as an exercise for graduate students in my area.
Today I noticed:
- Incentive compatibility: For example, the article says that there are different "types" of IC (dominant strategy, Bayes-Nash). These aren't different types of IC. IC is a constraint (or sometimes a desideratum), and one can impose it on problems which we solve under different rationality assumptions. (This isn't a very good statement either!) Also, Bayes-Nash is defined incorrectly (the definition given is for Nash more generally.)
- Strategyproof: This one is really dreadful. The concept is defined incorrectly at least once (and the mere fact that it is defined more than once in a single entry is not good): the claim is made that "strategyproof" is equivalent to incentive compatibility + individual rationality. NOT. Also, the rather absurd claim is made that the concept is "most natural to the theory of payment schemes for network routing". I can't even fathom what metric one might use to measure whether a concept is more or less "natural" in various settings, but in any case, it seems absurd on its face to privilege network routing applications over all other applications for which dominant strategy constructs (such as strategyproofness) are useful. I actually looked this one up because I heard someone use the concept incorrectly in a research presentation, and that reminded me that a careful definition for strategyproofness is rarely stated, though it is used quite often.
If you happen to pick up on one of these and do some editing, be sure to note it here!