# [Sequence announcement] Introduction to Mechanism Design

post by badger · 2014-04-30T16:21:31.652Z · LW · GW · Legacy · 12 commentsMechanism 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 directly, mechanism design provides tools and results for anyone interested in world optimization.

In this sequence, I'll touch on

- The basic mechanism design framework, including the revelation principle and incentive compatibility.
- The Gibbard-Satterthwaite impossibility theorem for strategyproof implementation (a close analogue of Arrow's Theorem), and restricted domains like single-peaked or quasilinear preference where we do have positive results.
- The power and limitations of Vickrey-Clarke-Groves mechanisms for efficiently allocating goods, generalizing Vickrey's second-price auction.
- Characterizations of incentive-compatible mechanisms and the revenue equivalence theorem.
- Profit-maximizing auctions.
- The Myerson-Satterthwaite impossibility for bilateral trade.
- Two-sided matching markets à la Gale and Shapley, school choice, and kidney exchange.

As the list above suggests, this sequence is going to be semi-technical, but my foremost goal is to convey the intuition behind these results. Since mechanism design builds on game theory, take a look at Yvain's Game Theory Intro if you want to brush up.

Various resources:

- For further introduction, you can start with the popular or more scholarly survey of mechanism design from the 2007 Nobel memoriam prize in economics.
- Jeff Ely has lecture notes and short videos to accompany an undergraduate class in microeconomic theory from the perspective of mechanism design.
- The textbook A Toolbox for Economic Design by Dimitrios Diamantaras is very accessible and comprehensive if you can get ahold of a copy.
- Tilman Börgers has a draft textbook intended for graduate students.
- Chapters 9-16 of Algorithmic Game Theory and chapters 10-11 of Multiagent Systems cover various topics in mechanism design from the perspective of computer scientists.
- Video lectures introducing market design and computational aspects of mechanism design.

I plan on following up on this sequence with another focusing on group rationality and information aggregation, surveying scoring rules and prediction markets among other topics.

Suggestions and comments are very welcome.

## 12 comments

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## comment by MarkL · 2014-05-01T12:22:55.479Z · LW(p) · GW(p)

Anyone do "mechanism design" in their day job? What are jobs that have aspects of this? (Besides implicitly, like every web startup ever, which is still interesting to think about.)

Replies from: badger, Lumifer## ↑ comment by badger · 2014-05-01T13:17:15.750Z · LW(p) · GW(p)

Aside from academic economists and computer scientists? :D Auction design has been a big success story, enough so that microeconomic theorists like Hal Varian and Preston McAfee now work at Google full time. Microsoft and other tech companies also have research staff working specifically on mechanism design.

As far as people that should have some awareness (whether they do or not): anyone implementing an online reputation system, anyone allocating resources (like a university allocating courses to students or the US Army allocating ROTC graduates to its branches), or anyone designing government regulation.

## comment by **[deleted]** ·
2014-04-30T21:07:27.174Z · LW(p) · GW(p)

What type of information would be prerequisite to understanding this sequence?

Replies from: badger## ↑ comment by badger · 2014-04-30T21:58:24.559Z · LW(p) · GW(p)

Some exposure to game theory. Otherwise, tolerance of formulas and a little bit of calculus for optimization.

At least, I hope that's the case. I've been teaching this to economics grad students for the past few years, so I know common points of misunderstanding, but can easily take some jargon for granted. Please call me out on anything that is unclear.

## comment by cursed · 2014-05-04T05:33:17.213Z · LW(p) · GW(p)

It'd be nice if you could go over why you think you'd be a good candidate to cover the subject.

Replies from: badger## comment by IlyaShpitser · 2014-05-01T12:14:24.047Z · LW(p) · GW(p)

I think that this is what we, as a civ, need to concentrate on if we are worried about inhuman unfriendly giants running around.