Francesco Feri

Bilateral Information Sharing in Oligopoly

We study the problem of information sharing in oligopoly, when sharing decisions are taken before the realization of private signals. Using the general model developed by Raith (1996), we show that if firms are allowed to make bilateral exclusive sharing agreements, then some degree of information sharing is consistent with equilibrium, and is a constant feature of equilibrium when the number of firms is not too small. Our result is to be contrasted with the traditional conclusion that no information is shared in common values situations with strategic substitutes - such as Cournot competition with demand shocks - when firms can only make industry-wide sharing contracts (e.g., a trade association).

Stochastic stability in networks with decay

Abstract This paper considers a stylized model of network formation in which relations among agents are subject to frictions, as described in Bala and Goyal [A non cooperative model of network formation, Econometrica 68 (2000) 1181–1231]. We analyze the process of network formation in a dynamic framework where self-interested individuals can form or delete links and, occasionally, make mistakes. Then, using stochastic stability, we identify the network structures to which the formation process will converge.

Error cascades in observational learning: An experiment on the Chinos game

The paper reports an experimental study based on a variant of the popular Chinos game, which is used as a simple but paradigmatic instance of observational learning. There are three players, arranged in sequence, each of whom wins a fixed price if she manages to guess the total number of coins lying in everybody’s hands. Our evidence shows that, despite the remarkable frequency of equilibrium outcomes, deviations from optimal play are also significant. And when such deviations occur, we find that, for any given player position, the probability of a mistake is increasing in the probability of a mistake of her predecessors. This is what we call an error cascade, which we rationalize by way of a simple model of “noisy equilibrium”.

On the Microstructure of Price Determination and Information Aggregation with Sequential and Asymmetric Information Arrival in an Experimental Asset Market

Experiments were conducted on an asset with the structure of an option. The information of any individual is limited, as if only the direction of movement of the option value known for a single period without information of the value from when movement was initiated. However, if all information of all insiders were pooled, the value of the option would be known with certainty. The results are the following: (1) Information becomes aggregated in the prices as if fully informative rational expectations operated; and (2) The mechanism through which information gets into the market is captured by a path dependent process that we term The Fundamental Coordination Principle of Information Transfer in Competitive Markets. The early contracts tend to be initiated by insiders who tender limit orders. The emergence of bubbles and mirages in the markets are coincident with failures and circumstances that prevent the operation of the Fundamental Principle.

Experimental Games on Networks: Underpinnings of Behavior and Equilibrium Selection

In this paper, we describe a series of laboratory experiments that implement specific examples of a general network structure. Specifically, actions are either strategic substitutes or strategic complements, and participants have either complete or incomplete information about the structure of a random network. Since economic environments typically have a considerable degree of complementarity or substitutability, this framework applies to a wide variety of settings. We examine behavior and equilibrium selection. The degree of equilibrium play is striking, in particular with incomplete information. Behavior closely resembles the theoretical equilibrium whenever this is unique; when there are multiple equilibria, general features of networks, such as connectivity, clustering, and the degree of the players, help to predict informed behavior in the lab. People appear to be strongly attracted to maximizing aggregate payoffs (social efficiency), but there are forces that moderate this attraction: (1) people seem content with (in the aggregate) capturing only the lions share of the efficient profits in exchange for reduced exposure to loss, and (2) uncertainty about the network structure makes it considerably more difficult to coordinate on a demanding, but efficient, equilibrium that is typically implemented with complete information.

Information sharing networks in linear quadratic games

We study the bilateral exchange of information in the context of linear quadratic games. An information structure is here represented by a non directed network, whose nodes are agents and whose links represent sharing agreements. We first study the equilibrium use of information given the network, finding that the extent to which a piece of information is observed by others affects the equilibrium use of it, in line with previous results in the literature. We then study the incentives to share information ex-ante, highlighting the role of the elasticity of payoffs to the equilibrium volatility of one’s own strategy and of opponents’ strategies. For the case of uncorrelated signals we fully characterise pairwise stable networks for the general linear quadratic game. For the case of correlated signals, we study pairwise stable networks for three specific linear quadratic games—Cournot Oligopoly, Keynes’ Beauty Contest and a Public Good Game—in which strategies are substitute, complement and orthogonal, respectively. We show that signals’ correlation favours the transmission of information, but may also prevent all information from being transmitted.

Network Formation with Endogenous Decay

This paper considers a model of economic network characterized by an endogenous architecture and frictions in the relations among agents as described in Bala and Goyal (2000). We propose a similar network model with the difference that frictions in the relations among agents are endogenous. Frictions are modeled as dependent on the result of a coordination game, played by every pair of directly linked agents and characterized by 2 equilibria: one efficient and the other risk dominant. The model has a multiplicity of equilibria and we produce a characterization of those are stochastically stable.

The Effect of Externalities Aggregation on Network Games Outcomes

We generalize results on the monotonicity of equilibria for network games with incomplete information. In those games players know the stochastic process of network formation and their own degree in the realized network, and decide an action whose payo depends on the strategic interaction in the network between their own action and a statistic (as, for example, the mean, the maximum or the minimum) of neighbors’ actions. We show that, even under degree independence, not only the distinction between strategic complements and strategic substitutes is important in determining the nature of Bayesian Nash equilibria, but also the nature itself of the statistic.

Bargaining or Searching for a Better Price? - An Experimental Study

This experimental study investigates two bargaining games with two-sided incomplete information between a seller and a buyer. In the first game with no outside options many subjects do not use the incomplete information to their advantage as predicted. We find that a model with adjusting priors better explains observed behavior. The second game gives the buyer the option to buy via search or return to bargaining. Here many buyers choose a bargaining agreement when a search outcome is predicted. For those who opt out, search outcomes are overall efficient and behavior is relatively close to the optimal search policy.

Information Sharing Networks in Oligopoly

We study the incentives of oligopolistic firms to share private information on demand parameters. Differently from previous studies, we consider bilateral sharing agreements, by which firms commit at the ex-ante stage to truthfully share information. We show that if signals are i.i.d., then pairwise stable networks of sharing agreements are either empty or made of fully connected components of increasing size. When linking is costly, non complete components may emerge, and components with larger size are less densly connected than components with smaller size. When signals have different variances, incomplete and irregular network can be stable, with firms observing high variance signals acting as critical nodes. Finally, when signals are correlated, the empty network may not be pairwise stable when the number of firms and/or correlation are large enough.