badger

Despite dictatorships being the only strategyproof mechanisms in general, more interesting strategyproof mechanisms exist for specialized settings. I introduce single-peaked preferences and discrete exchange as two fruitful domains. Strategyproofness is a very appealing property. When interacting with a strategyproof mechanism, a person is never worse off for being honest (at...

In which the limits of dominant-strategy implementation are explored. The Gibbard-Satterthwaite dictatorship theorem for unrestricted preference domains is stated, showing no universal strategyproof mechanisms exist, along with a proof for a special case. Due to the Revelation Principle, most design questions can be answered by studying incentive compatible mechanisms, as...

In which the Revelation Principle is introduced, showing all mechanisms can be reduced to incentive compatible mechanisms. With this insight, a solution (of sorts) is given to the public good problem in the last post. Limitations of the Revelation Principle are also discussed. The formalism I introduced last time will...

tl;dr Mechanism design studies how to design incentives for fun and profit. A puzzle about whether or not to paint a room is posed. A modeling framework is introduced, with lots of corresponding notation. Mechanism design is a framework for constructing institutions for group interactions, giving us a language for...

Mechanism design is the theory of how to construct institutions for strategic agents, spanning applications like voting systems, school admissions, regulation of monopolists, and auction design. Think of it as the engineering side of game theory, building algorithms for strategic agents. While it doesn't have much to say about rationality...

Rereading Hofstadter's essays on superrationality prompted me to wonder what strategies superrational agents would want to commit to in asymmetric games. In symmetric games, everyone can agree on outcome they'd like to jointly achieve, leaving the decision-theoretic question of whether the players can commit or not. In asymmetric games, life...

Mark Eichenlaub posted a great little case-study about the difficulty of updating beliefs, even over trivial matters like the slope of a baseball field. The basic story of Bayes-updating assumes the likelihood of evidence in different states is obvious, but feedback between observations and judgments about likelihood quickly complicate the...