Strategy-proofness in experimental matching markets

We introduce two novel matching mechanisms, Reverse Top Trading Cycles (RTTC) and Reverse Deferred Acceptance (RDA), with the purpose of challenging the idea that the theoretical property of strategy-proofness induces high rates of truth-telling in economic experiments. RTTC and RDA are identical to the celebrated Top Trading Cycles (TTC) and Deferred Acceptance (DA) mechanisms, respectively, in all their theoretical properties except that their dominant-strategy equilibrium is to report one’s preferences in the order opposite to the way they were induced. With the focal truth-telling strategy being out of equilibrium, we are able to perform a clear measurement of how much of the truth-telling reported for strategy-proof mechanisms is compatible with rational behaviour and how much of it is caused by confused decision-makers following a default, focal strategy without understanding the structure of the game. In a school-allocation setting, we find that roughly half of the observed truth-telling under TTC and DA is the result of naïve (non-strategic) behaviour. Only 14–31% of the participants choose actions in RTTC and RDA that are compatible with rational behaviour. Furthermore, by looking at the responses of those seemingly rational participants in control tasks, it becomes clear that most lack a basic understanding of the incentives of the game. We argue that the use of a default option, confusion and other behavioural biases account for the vast majority of truthful play in both TTC and DA in laboratory experiments.

     

COLLEGE ADMISSIONS AND THE ROLE OF INFORMATION: AN EXPERIMENTAL STUDY*

Three well‐known matching mechanisms designed to solve the college admissions problems are analyzed in the experimental laboratory in different informational settings. We observe that when the level of information is significantly increased, the proportion of schools and teachers that submit their true preferences decreases. This affects largely the efficiency and stability of the Gale–Shapley and the Boston mechanisms. The TTC mechanism is less sensitive to information and outperforms the other two mechanisms in terms of efficiency and stability, and it is as successful as them in extracting private information.     

Multibidding game under uncertainty

This paper considers situations in which a group of agents has to decide whether to carry out a given public project or its alternative when agents hold private information. I use the budget-balanced multibidding mechanism (Pérez-Castrillo and Wettstein in Am Econ Rev 5:1577–1587, 2002) according to which the game to be played by participants has only one stage and simple rules that can be applied in a wide range of situations. It is shown that the symmetric equilibria of the multibidding game deliver ex-post efficient outcomes if the number of agents is two, for any underlying symmetric distribution characterizing uncertainty, or is very large.