Recently dozens of school districts and college admissions systems around the world have reformed their admission rules. As a main motivation for these reforms the policymakers cited strategic flaws of the rules: students had strong incentives to game the system, which caused dramatic...

Vulnerability to manipulation is a threat to successful matching market design. However, some manipulation is often inevitable and the mechanism designer wants to compare manipulable mechanisms and pick the best. Real-life examples include reforms in the entry-level medical labor market in the...

Recently, many matching systems around the world have been reformed. These reforms responded to objections that the matching mechanisms in use were unfair and manipulable. Surprisingly, the mechanisms remained unfair even after there forms: the new mechanisms may induce an out come with a...

We study practically relevant aspects of popularity in two-sided matching where only one side has preferences. A matching is called popular if there does not exist another matching that is preferred by a simple majority. We show that for a matching to be popular it is necessary and sufficient...

We study voting rules with respect to how they allow or limit a majority to dominate minorities. For this purpose we propose a novel quantitative criterion for voting rules: the qualified mutual majority criterion (q, k)-MM. For a fixed total number of m candidates, a voting rule satisfies (q,...

We use a range of dictator game experiments to investigate why people avoid information. Dictators in our experiment know their own payoffs and can choose whether to learn the payoffs of the recipient. We vary whether dictators can learn the recipient's payoff before or after they are presented...