Financial Applications of Random Matrix Theory: a short review

We discuss the applications of Random Matrix Theory in the context of financial markets and econometric models, a topic about which a considerable number of papers have been devoted to in the last decade. This mini-review is intended to guide the reader through various theoretical results (the Marcenko-Pastur spectrum and its various generalisations, random SVD, free matrices, largest eigenvalue statistics, etc.) as well as some concrete applications to portfolio optimisation and out-of-sample risk estimation.Comment: To appear in the "Handbook on Random Matrix Theory", Oxford University Pres

The Endogenous Evolution of Market Institutions: An Experimental Investigation

We study an experimental market in which the structure of the information flows is endogenized. When making an offer, traders choose not only the price at which they are prepared to trade, but also the subset of traders they want to inform about the offer. This design allows for two extreme institutions as special cases. If traders always inform every other trader about each offer, the resulting institution is equivalent to a double auction. If, on the other hand, traders always inform only one other trader about each offer, the resulting institution is equivalent to a decentralized bargaining market. The institution that actually evolved in the experiments, however, was in between the two extreme cases. Subjects typically informed all traders of the other market side, but none of their own side. This endogenously evolving institution, however, turned out to have the same properties as the double auction.market institution;information structure;efficiency

Why Announce Leadership Contributions? An Experimental Study of the Signaling and Reciprocity Hypotheses

Why do fundraisers announce initial contributions to their charity?Potential explanations are that these announcements cause future donors to increase their contributions, either because they want to reciprocate the generosity of earlier donors, or because the initial contributions are seen as a signal of the charity's quality.Using experimental methods we investigate these two hypotheses.When only the first donor is informed of the public good's quality, subjects not only copy the initial contribution, but the first donor also correctly anticipates this response.While this result is consistent with both the signaling and the reciprocity explanations, the latter is unlikely to be the driving force.The reason is that announcements have no effect on contribution levels when the quality of the public good is common knowledge.Thus our results provide strong support for the signaling hypothesis.funds;information;public goods

LYING ABOUT WHAT YOU KNOW OR ABOUT WHAT YOU DO?

We compare communication about private information to communication about actions in a one-shot 2-person public good game with private information. The informed player, who knows the exact return from contributing and whose contribution is unobserved, can send a message about the return or her contribution. Theoretically, messages can elicit the uninformed player's contribution, and allow the informed player to free-ride. The exact language used is not expected to matter. Experimentally, however, we find that free-ride depends on the language: the informed player free-rides less-and thereby lies less frequently-when she talks about her contribution than when she talks about the return. Further experimental evidence indicates that it is the promise component in messages about the contribution that leads to less free-ride and less lying. © 2013 by the European Economic Association

Lying About What you Know or About What you Do? (replaces CentER DP 2010-033)

We compare communication about private information to communication about actions in a one- shot 2-person public good game with private information. The informed player, who knows the exact return from contributing and whose contribution is unobserved, can send a message about the return or her contribution. Theoretically, messages can elicit the uninformed player's contribution, and allow the informed player to free-ride. The exact language used is not expected to matter. Experimentally, however, we find that free-riding depends on the language: the informed player free-rides less, and thereby lies less frequently, when she talks about her contribution than when she talks about the return. Further experimental evidence indicates that it is the promise component in messages about the contribution that leads to less free-riding and less lying.Information transmission;lying;communication;experiment