Comment on “Correlated information, mechanism design and informational rents” [J. Econ. Theory 123 (2) (2005) 210–217]

We amend an error in [S. Parreiras, Correlated information, mechanism design and informational rents, J. Econ. Theory 123 (2005) 210–217]. Consequently, it is in general not possible to reinterpret a mechanism design model that violates the spanning condition of Crémer and McLean [J. Crémer, R. McLean, Full extraction of the surplus in bayesian, dominant strategy auctions, Econometrica 56 (1988) 1247–1258] as one in which agents hold private information about the informativeness of their signals about other agents? types. Instead, such an interpretation is warranted only when the weights used to span an agent?s set of beliefs stand in a singular relation with the prior type distribution that is known as an alternative characterization of Blackwell dominance.     

Trade openness and the informational efficiency of emerging stock markets

This paper examines the empirical link between trade openness and the informational efficiency of stock markets in 23 developing countries. Our fixed effects panel regression results document a significant negative relation between trade openness and stock return autocorrelations only when the de facto measure is used. On this basis, we argue that a greater level of de facto trade openness is associated with a higher degree of informational efficiency in these emerging stock markets because the former signals higher future firm profitability, and investors tend to react faster to information when there is less uncertainty about a firm's future earnings or cash flows. Further analyses find no significant association between the extent of financial openness and the degree of informational efficiency.     

Rational expectations equilibrium with conditioning on past prices: A mean-variance example

The paper uses an intertemporal mean-variance model of the market for a dividend-paying risky asset to analyse rational expectations equilibria when all agents condition their expectations on past rather than current prices. The main result shows that if the time span between successive market periods is short, the market will approximate full informational efficiency arbitrarily closely, yet the returns to being informed are bounded away from zero. This contrasts with the Grossman-Stiglitz proposition that markets cannot come close to informational efficiency if the acquisition of information is costly.     

Meade on indicative planning: A review of informational problems

In The Theory of Indicative Planning Meade develops a theoretical model of indicative planning that reduces uncertainty by gathering information from economic agents about their future intentions. Since the purpose of indicative planning is to provide agents with additional information, its effectiveness depends importantly on the accuracy of the information it supplies. Recent developments in the literature on the economics of information and uncertainty suggest that serious informational problems may impair the accuracy of planning forecasts and reduce the effectiveness of the plan.     

Aggregate information cascades

We introduce a new model of aggregate information cascades where only one of two possible actions is observable to others. Agents make a binary decision in sequence. The order is random and agents are not aware of their own position in the sequence. When called upon, they are only informed about the total number of others who have chosen the observable action before them. This informational structure arises naturally in many applications. Our most important result is that only one type of cascade arises in equilibrium, the aggregate cascade on the observable action. A cascade on the unobservable action never arises.     

Robust monopoly pricing

We consider a robust version of the classic problem of optimal monopoly pricing with incomplete information. In the robust version, the seller faces model uncertainty and only knows that the true demand distribution is in the neighborhood of a given model distribution. We characterize the pricing policies under two distinct decision criteria with multiple priors: (i) maximin utility and (ii) minimax regret. The equilibrium price under either criterion is lower then in the absence of uncertainty. The concern for robustness leads the seller to concede a larger information rent to all buyers with values below the optimal price without uncertainty.     

Pricing Monitoring Uncertainty in Climate Policy

This article assesses the environmental and economic efficiency of three different approaches to treat monitoring uncertainty in climate policy, namely prescribing uncertainty, setting minimum certainty thresholds and pricing uncertainty through a discount. Our model of the behavior of profit-maximizing agents demonstrates that under the simplest set of assumptions the regulator has no interest in reducing monitoring uncertainty. However, in the presence of information asymmetry, monitoring uncertainty may hamper the economic and environmental performance of climate policy due to adverse selection. In a mandatory policy, prescribing a reasonable level of uncertainty is preferable if the regulator has enough information to determine this level. For voluntary mechanisms, such as carbon offsets, allowing agents to set their own monitoring uncertainty below a maximum threshold or discounting carbon revenues in proportion to monitoring uncertainty are the best approaches for the regulator to mitigate the negative effects of information asymmetry. These conclusions are much more pronounced when agents do not accrue revenues from their mitigation action, other than carbon. Our analysis of monitoring uncertainty under information asymmetry, which results in heterogeneity in the agents’ benefits from abatement, generalizes the classical trade-off between production efficiency and information rents.     

Optimal size, optimal timing and optimal financing of an investment

Corporate investment is an important determinant of economic well-being. The existing literature identifies optimal investment size and timing without the possibility of debt financing, as well as the effect of debt financing on investment timing without the option to choose investment size. This paper contributes to the literature by identifying the optimal size, optimal timing and optimal financing for an investment when the firm controls all three decisions (as it usually does in practice). The investment size and investment trigger are generally positively related: when investment is delayed (accelerated) it is larger (smaller) in size, thus the overall effect on investment is ambiguous. However, when tax rate or bankruptcy cost is increased, the trigger rises and size falls, hence the effect on investment is unambiguously negative. The effect of debt financing on investment depends on the amount of debt used; with the optimal amount of debt, investment is delayed relative to the no-debt case, and this delay can be economically significant; however, the investment, when eventually made, will be larger in size. Overall, it is not appropriate to ignore either the firm’s ability to choose investment size or its option to use debt financing, when modeling the investment decision.     

On spatial equilibria in a social interaction model

Social interactions are at the essence of societies and explain the gathering of individuals in villages, agglomerations, or cities. We study the emergence of multiple agglomerations as resulting from the interplay between spatial interaction externalities and competition in the land market. We show that the geography of the spatial economy affects significantly the properties of spatial equilibria. In particular, when agents locate on an open land strip (line segment), a single city emerges in equilibrium. In contrast, when the spatial economy extends along a closed land strip (circumference), multiple equilibria with odd numbers of cities arise. Spatial equilibrium configurations involve a high degree of spatial symmetry in terms of city size and location, and can be Pareto-ranked.     

Estimating Demand for Local Telephone Service with Asymmetric Information and Optional Calling Plans

In this paper, I study the theoretical and econometric implications of agents' uncertainty concerning their future consumption when a monopolist offers them either a unique, mandatory nonlinear tariff or a choice in advance from a menu of optional two–part tariffs. Agents' uncertainty is resolved through individual and privately known shocks to their types. In such a situation the principal may screen agents according to their ex ante or ex post type, by offering either a menu of optional tariffs or a standard nonlinear schedule. The theoretical implications of the model are used to evaluate a tariff experiment run by South Central Bell in two cities in Kentucky in 1986. The empirical approach explicitly accounts for the existence of informational asymmetries between local telephone users and the monopolist, leading to different, nested, econometric specifications under symmetric and asymmetric information. The empirical evidence suggests that there exists a significant asymmetry of information between consumers and the monopolist under both tariff regimes. All expected welfare components failed to increase with the introduction of optional tariffs for the estimated value of the parameters.     

Informational efficiency: ranking markets

Summary. The paper studies informational properties of three types of imperfectly competitive markets: a one-signal speculative market (OSS market) in which agents have only private information about the fundamental value (v) of the risky asset traded, a two-signal speculative market (TSS market) in which agents have private information about both v and the asset supply, and a market in which agents are endowed with both information about v and shares of the risky asset traded. In this last market (JA market), agents have joint activities: they trade for both speculative and hedging purposes. It is shown that (i) the JA market and the OSS market are the most and the least efficient, respectively, and (ii) the levels of informational efficiency in the three markets are inversely correlated with the intensities with which traders use their private information about the fundamental value of the asset. Received May 28, 1999; revised version: May 28, 1999     

A dynamic model of expectations equilibrium

This paper describes a dynamic information adjustment process which achieves (rational) expectations equilibria for stochastic exchange environments. An informational temporary equilibrium is an exchange equilibrium in which agents' expectations are conditioned on their initial information and market data generated in previous informational temporary equilibria. An equilibrium is a temporary equilibrium which reveals no further information. This process leads to an equilibrium even when the data observed by agents is insufficient to permit the existence of an expectations equilibrium.     

Informational externalities with lump-sum sampling

Abstract .  We consider a game of strategic experimentation where agents are restricted to an all-or-nothing sampling strategy. The strategic interaction between agents due to informational externalities is affected by the sizes of the experimentation samples and the sensitivity of information to changes in sample sizes. There is experimentation only if the overall sample is large enough. Equilibrium may involve optimal, insufficient or excessive experimentation relative to a second-best welfare benchmark. This unusual over-experimentation result is associated not necessarily with large samples but with a low elasticity of the value of information with respect to the sample size.     

Hiding an inconvenient truth: Lies and vagueness

When truth conflicts with efficiency, can verbal communication destroy efficiency? Or are lies or vagueness used to hide inconvenient truths? We consider a sequential 2-player public good game in which the leader has private information about the value of the public good. This value can be low, high, or intermediate, the latter case giving rise to a prisoners? dilemma. Without verbal communication, efficiency is achieved, with contributions for high or intermediate values. When verbal communication is added, the leader has an incentive to hide the precise truth when the value is intermediate. We show experimentally that, when communication must be precise, the leader frequently lies, preserving efficiency by exaggerating. When communication can be vague, the leader turns to vague messages when the value is intermediate. Thus, she implicitly reveals all values. Interestingly, efficiency is preserved, since the follower does not seem to realize that vague messages hide inconvenient truths.     

Extracting Resource Deposits of Unknown Size: Optimal Order

Abstract. The optimal order of extracting resource deposits of unknown size depends on the informational characteristics of the extraction process. This paper fills the gap between two strands of literature. The first strand is about the optimal extraction of single reserve under stock-size uncertainty. The second strand is about the optimal order of extraction of deposits of known sizes. Our emphasis on the premium for resolution of uncertainty complements Solow and Wan's shadow surcharge when extraction moves from a low-cost deposit to a high-cost one.     

Information and size of coalitions

We consider a set of asymmetrically informed agents, where the information of each trader is susceptible of being altered when she becomes a member of a coalition. For this, we consider a general rule that depending on the coalition, a signal (or an information partition) is assigned to each member of the coalition. We set examples showing that Grodal’s (Econometrica 40:581–583, 1972), Schmeidler’s (Econometrica 40:579–580, 1972) and Vind’s (Econometrica 40:585–586, 1972) core characterizations of a continuum economy may fail in this general informational setting. However, under mild assumptions on the rule, we extend Schmeidler’s and Vind’s results to economies that allocate information to agents in each coalition according to the rule. We then focus on information mechanisms based on the size of coalitions and provide a general characterization result for the corresponding cores. Moreover, we pay close attention to the rule that assigns the shared information to each member of specific coalitions. We prove that the resulting cores are exactly the same independently of whether arbitrarily small or large coalitions share information.     

Asymmetric information in bilateral trade and in markets: An inversion result

I consider bilateral trade between a seller and a buyer with private valuations. The seller makes a take-it-or-leave-it price offer. If the seller observes the buyer?s valuation (symmetric information), bilateral trade is trivially efficient. If the seller cannot observe the valuation (asymmetric information), bilateral trade is inefficient. This bilateral trading game is embedded into a large matching market. In the steady-state equilibrium of the market game, the relation between the informational regime and efficiency is inverted: With small frictions efficiency obtains if information is asymmetric. If information is symmetric, however, the trading outcome can be very inefficient—even if frictions vanish.     

The trade-offs from pattern bargaining with uncertain production costs

Pattern bargaining is a negotiating strategy that is often employed by industry-wide unions in oligopolistic industries to set wages. The conventional wisdom is that pattern bargaining “takes labor out of competition” and therefore softens bargaining between the union and firms, resulting in higher industry wide wages. However, this does not explain why firms agree to pattern bargaining. We introduce a model in which the agents face uncertainty about the relative product-market positions of the firms and compare the trade-offs involved in adopting different bargaining mechanisms. We show that with sufficient heterogeneity in non-labor costs, there are situations in which both the union and the firms prefer pattern bargaining. We also show that in such situations, the adoption of pattern bargaining harms consumers. This provides an explanation as to how pattern bargaining can arise in equilibrium and why there is often strong political opposition to it.     

Transaction costs and informational cascades in financial markets

We study the effect of transaction costs (e.g., a trading fee or a transaction tax, like the Tobin tax) on the aggregation of private information in financial markets. We implement a financial market with sequential trading and transaction costs in the laboratory. According to theory, eventually all traders neglect their private information and abstain from trading (i.e., a no-trade informational cascade occurs). We find that, in the experiment, informational no-trade cascades occur when theory predicts they should (i.e., when the trade imbalance is sufficiently high). At the same time, the proportion of subjects irrationally trading against their private information is smaller than in a financial market without transaction costs. As a result, the overall efficiency of the market is not significantly affected by the presence of transaction costs.     

Allocation of resources in a team

The informational efficiency of “price” and “demand” messages in a resource allocation mechanism is studied here with the aid of the theory of teams¹. In the usual analysis of adjustment mechanisms (tâtonnement, decomposition), the adjustment process is assumed to run to completion, so that all the allocation and resource decisions can be made on the basis of enough information to guarantee optimal decisions². If, however, decisions must be made before the adjustment process is completed, say, after only a few iterations, then the decisions must be taken with limited information, and thus under conditions of uncertainty. This paper discusses a simple model in an attempt to examine explicitly these problems of uncertainty and limited information. A set of enterprise managers are assumed to produce various commodities, using scarce resources allocated to the enterprises by a resource manager. The enterprise managers also make decisions that affect their individual outputs. Varous kinds of communication among the managers, together with the corresponding information structures, are formulated, including the communication of price and demand messages. Optimal decision rules for the managers are calculated for the objective of maximizing the expected value of an index of total output. (It is assumed that the production functions and the supplies of scarce resources are stochastic, but are observed by the respective managers.) It is shown that optimal decision rules based on a single exchange of price and demand messages, between the resource manager on the one hand and the enterprise managers on the other, produces as good results as rules based on (1) complete information for the resource manager, and (2) information about the supplies of resources on the part of the enterprise managers. Furthermore, these price and demand messages produce approximately fully optimal results when the number of enterprises is large. However, the optimal decisions of the enterprise managers do not maximize profits, at least relative to any price that is the same for all enterprises. An assumption that the production functions are quadratic plays a key role.