a common agency with incomplete information in the present article i demonstrate that forming a common agency by oligopolistic firms may not be to their advantage if agents have access to private information about their costs bernheim and whinston 1985 1986 pointed out that a common agency allows the firms to sustain the collusive outcome by giving them a vehicle to internalize the externality generated by their pricing or output decisions if agents have access to private information the advantage pointed out by bernheim and whinston may be more than outweighed by the possible existence of an informational disadvantage specifically if the unit costs of different potential agents are correlated the firm may be more successful in extracting the informational rents of its agent if it contracts with an independent agent and not with the same agent as its rival firm when oligopolistic firms contract with independent agents the revenues of one firm reveal implicit information about the unit costs of agents serving competing firms in the same industry however if the unit costs of different agents are correlated revenues also reflect information about the unit cost of the firm s own agent this additional information transmitted by revenues cannot be controlled by the agent s reporting behavior as a result if the firm conditions its agent s payoff upon revenues it can limit the informational rents that this agent can secure due to the existence of private information this possibility of limiting its agent s informational rents is eliminated if the firm contracts with the same agent as its rivals with a common agency the agent can manipulate the reports delivered to all the firms thus reducing the options available to each of them various patterns of agency relationship exist in markets where oligopolistic producers

optimal regulation with unknown demand and cost functions abstract this paper presents an analysis of optimal regulation of a firm that has private information about both its cost and demand functions an earlier paper on the same topic lewis and sappington rand j econ 19 1998 438 457 is reviewed a difficulty with their analysis is discussed and an alternative formulation of their model is proposed two broad classes of problem are considered i the case where social and private incentives are roughly aligned which implies optimal prices are weakly above marginal costs and ii the case where social and private incentives diverge which implies pricing below marginal cost may be optimal journal of economic literature classification numbers d42 d82 l51

designing supply contracts contract type and information asymmetry this paper studies the value to a supplier of obtaining better information about a buyer s cost structure and of being able to offer more general contracts we use the bilateral monopoly setting to analyze six scenarios three increasingly general contracts wholesale pricing schemes two part linear schemes and twopart nonlinear schemes each under full and incomplete information about the buyer s cost structure we allow both sides to refuse to trade by explicitly including reservation profit levels for both for the supplier this is implemented through a cutoff policy we derive the supplier s optimal contracts and profits for all six scenarios and examine the value of information and of more general contracts our key findings are as follows first the value of information is higher under two part contracts second the value of offering two part contracts is higher under full information and third the proportion of buyers the supplier will choose to exclude can be substantial

optimal risk allocation for regulated monopolies and consumers abstract the model shows how a regulated monopolist s price should change as random cost and demand parameters are revealed the regulator has a ramsey type problem with a linear tariff a trade off between allocative efficiency and risk sharing typically exists the attitudes of the consumer and the firm to both income and price risk determine how the price should move sufficient conditions are found for price adjustment schemes used in practice to be optimal these schemes include full partial and zero pass through of marginal costs and price caps average cost pricing and caps on total revenue for demand risk

bubbles crashes and endogenous expectations in experimental spot asset markets1 spot asset trading is studied in an environment in which all investors receive the same dividend from a known probability distribution at the end of each of t 15 or 30 trading periods fourteen of twenty two experiments exhibit price bubbles followed by crashes relative to intrinsic dividend value when traders are experienced this reduces but does not eliminate the probability of a bubble the regression of changes in mean price on lagged excess bids number of bids minus the number of offers in the previous period p pt a f b 1 o l supports the hypothesis that a e d the one period expected value of the dividend and that f 0 where excess bids is a surrogate measure of excess demand arising from homegrown capital gains losses expectations thus when bt 1 o goes to zero we have convergence to rational expectations in the sense of fama 1970 that arbitrage becomes unprofitable the observed bubble phenomenon can also be interpreted as a form of temporary myopia tirole 1982 from which agents learn that capital gains expectations are only temporarily sustainable ultimately inducing common expectations or priors tirole 1982 four of twenty six experiments all using experienced subjects yield outcomes that appear to the chart s eye to converge early to rational expectations although even in these cases we get 0 and small price fluctuations of a few cents that invite scalping

the bubble game an experimental study of speculation we propose a bubble game that involves sequential trading of an asset commonly known to be valueless because no trader is ever sure to be last in the market sequence the game allows for a bubble at the nash equilibrium when there is no cap on the maximum price we run experiments both with and without a price cap structural estimation of behavioral game theory models suggests that quantal responses and analogy based expectations are important drivers of speculation

classroom games speculation and bubbles in an asset market this paper describes a classroom exercise in which students trade assets of uncertain value in a sequence of market periods assets pay one dollar dividends at the end of each period but once the dividend is paid there is fixed probability that the asset will be destroyed dividends and probabilities are chosen so that the fundamental value is constant over time speculative bubbles can be caused by divergent expectations about other traders valuations of the asset this exercise provides an interactive framework that facilitates discussions of discounting rational expectations and backward induction

the chinese warrants bubble in 2005 2008 over a dozen put warrants traded in china went so deep out of the money that they were almost certain to expire worthless nonetheless each warrant was traded more than three times each day at substantially inflated prices this bubble is unique in that the underlying stock prices make warrant fundamentals publicly observable and that warrants have predetermined finite maturities this sample allows us to examine a set of bubble theories in particular our analysis highlights the joint effects of short sales constraints and heterogeneous beliefs in driving bubbles and confirms several key findings of the experimental bubble literature jel g12 g13 o16 p34

regulating a monopolist with unknown demand and cost functions we consider the design of regulatory policy when the regulator is imperfectly informed about both the firm s cost function and the demand function it faces to some extent the optimal policy here is the natural combination of the optimal policies when there is uncertainty only about either demand or cost important qualitative differences also exist however for example it may be optimal to set prices below marginal cost and the pricing authority delegated to the firm may be more limited when there is uncertainty about both cost and demand

surplus maximization and optimality i identify assumptions under which policies that maximize expected surplus are pareto optimal even when expected consumer surplus does not even locally represent preferences over price income lotteries besides the oft made partial equilibrium assumptions that only one price varies and that income changes do not aect demand the two other assumptions are that every consumer s indirect utility function is supermodular in price and income and policies order prices by a single crossing property supermodularity holds precisely if relative risk aversion exceeds the income elasticity of demand a mild condition the single crossing property appears strong but holds in many applications that use expected surplus

the bubble game a classroom experiment we propose a simple classroom experiment on speculative bubbles the bubble game this game is useful to discuss about market efficiency and trading strategies in a financial economics course and about behavioral aspects in a game theory course at all levels the bubble game can be played with any number of students as long as this number is strictly greater than one students sequentially trade an asset which is publicly known to have a fundamental value of zero if there is no cap on asset prices speculative bubbles can arise at the nash equilibrium because no trader is ever sure to be last in the market sequence otherwise the nash equilibrium involves no trade bubbles usually occur with or without a cap on prices traders who are less likely to be last and have less steps of reasoning to perform to reach equilibrium are in general more likely to speculate

monopoly regulation under asymmetric information prices versus quantities we compare two instruments to regulate a monopoly that has private information about its demand or costs fixing either the price or quantity for each instrument we consider sophisticated screening and simple bunching mechanisms we characterize the optimal mechanisms and compare their welfare performance with unknown demand and increasing marginal costs the sophisticated price mechanism dominates that of quantity whereas the sophisticated quantity mechanism may prevail when marginal costs decrease the simple price mechanism dominates that of quantity when marginal costs decrease but the opposite may arise if marginal costs increase with unknown costs both instruments are equivalent

exotics and electrons electric power crises and the financial risk management this article models the decisions of a regulated utility that has the option of meeting excess demand by buying power on the spot markets the risk associated with the cost of meeting excess consumer demand can be hedged by trading in a financial derivatives market we show that the optimal financial hedge position for an individual utility is a nonlinear mixture of price risk and quantity risk hedging the ability to form these hedges in financial markets can increase spot price volatility the availability of derivatives markets can also lower the value of long term power contracts and baseload supply

regulating an oligopoly with unknown costs abstract we examine the problem of a planner who is regulating an oligopoly with unknown costs we provide a complete characterization of the optimal mechanism which takes the following simple form firm s which report low costs produce together the first best output corresponding to this low cost and firm s which report high costs produce nothing when all firms report high costs only the ex ante least efficient firm produces the entire output and all the other firms produce nothing we show that under mild conditions as the number of firms increases the planner attains the same welfare level as if he had complete information of low cost

regulating a dominant firm unknown demand and industry structure in this article we study the optimal regulation of a dominant firm when an unregulated firm actively competes generally the existence of an active rival imposes new and binding constraints on regulatory problems we characterize optimal policies both when demands are known complete information and unknown incomplete information to the regulator optimal policies under complete information may set the price at the dominant firm above or below its marginal cost optimal policies under incomplete information may be either pooling or separating constant over a range of the prior distribution of the firm s private information and leave no information rent to the firm

verifiable and non verifiable anonymous mechanisms for regulating a polluting monopolist abstract optimal regulation of a polluting natural monopolist must correct for both external damages and market power to achieve a social optimum existing non bayesian regulatory methods require knowledge of the demand function while bayesian schemes require knowledge of the underlying cost distribution we introduce mechanisms adapted to use less information our p rice based s ubsidy ps mechanisms give the firm a transfer that matches or approximates the incremental surplus generated each period the regulator need not observe the abatement activity or know the demand cost or damage functions of the firm all of the mechanisms induce the firm to price at marginal social cost either immediately or asymptotically

regulating without cost information the incremental surplus subsidy scheme the authors propose a regulatory mechanism called the incremental surplus subsidy iss scheme that can be implemented even when the regulato r has no knowledge of the monopolist s cost structure the regulator need only share the firm s knowledge of demand which may be imperfec t and be able to observe with a lag the firm s expenditures the i ss scheme induces the firm to set marginal cost prices to minimize p roduction costs and to undertake efficient investment levels it als o severely limits the firm s rents and eliminates them altogether if the firm s discount rate is known copyright 1988 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

price versus quantity monitoring in an adverse selection context this article explores the relative usefulness of price information over quantity information the main finding is that price monitoring can induce a sales level that is greater than the full information sales level this imposes additional selling costs on the agent and reduces that agent s rents the analysis identifies sufficient conditions for the principal to prefer price monitoring over quantity monitoring business format franchises exhibit many of the features of the setting analyzed here and the article s findings have implications for designing information systems in that sector of the economy

effects of asymmetric information on airport congestion management mechanisms abstract we study and compare three different mechanisms for capacity slot allocation in a congested airport when airlines have one dimensional private information direct allocation of slots differentiated tolls and slot auctions with perfect information direct allocation is a first best policy which can be implemented through pigouvian taxes or slot auctions the mechanisms are equivalent in terms of social welfare with the introduction of asymmetric information this equivalence is lost direct allocation is always ex post inefficient and in some cases tolls and subsequent quantity delegation is a better alternative social welfare wise auctions may be superior or inferior to tolls we further show that naive application of pigouvian tolls is sub optimal when imperfect information exists

deregulation and quality abstract this paper analyses within a static model the effect of quality concern on optimal market structure it focuses on cases where industry quality has public good like features and is not contractible it is shown that the introduction of competition raises a free rider problem which depresses quality the smaller producer free rides on its competitor investment which as a result underinvests to encourage the efficient producer to provide quality the regulator diminishes the market share of the opportunistic producer and chooses more often a monopoly however when quality is verifiable the introduction of competition entails no welfare loss whether the regulator observes total quality outcome or individual contributions

on efficiency inducing taxation for a non renewable resource monopolist the problem of using taxes to induce a monopolist supplier of a non renewable resource to extract efficiently has been solved under the assumption that the government has perfect information about the monopolist s cost function and reserves and is able to precommit to an entire sequence of taxes over time we extend this literature by constructing an efficiency inducing tax mechanism that does not require the government to have any information about the cost function or reserves and which does not require it to precommit to a sequence of taxes over time

a simple model of search engine pricing we present a simple model of how a monopolistic search engine optimally determines the average relevance of firms in its search pool in our model there is a continuum of consumers who use the search engine s pool and there is a continuum of firms whose entry to the pool is restricted by a price per click set by the search engine we show that a monopolistic search engine may have an incentive to set a relatively low price per click that encourages low relevance advertisers to enter the search pool in general the ratio between the marginal and average relevance in the search pool induced by the search engine s policy is equal to the ratio between the search engine s profit per consumer and the equilibrium product price these conclusions do not change if the search engine charges a fixed access fee rather than a price per click a search engine is a platform that serves a two sided market it is based on a technology that potentially improves the quality of consumer search before the advent of internet search engines yellow pages were the closest example of a search engine firms pay to be included in the yellow pages with various degrees of prominence the yellow pages organise the set of firms according to some categorisation system in internet environments consumers use search engines by submitting a query in a language dictated by the search engine the objects that the query elicits depend on the search engine s

structural estimation of congestion costs abstract we estimate a structural model of congestion costs using a bayesian nash equilibrium approach the individual s preference for traveling depends on the anticipated level of congestion which in turn is determined by travelers decisions of mobility the model is estimated using a french transportation household survey results confirm the presence of incomplete information and show that aversion to congestion is 6 6 lower during peak times than during off peak times a traveler s willingness to pay to save 1 min in traffic is estimated at 0 73 euros during peak times and 0 25 euros during off peak times

prominence and consumer search this article examines the implications of prominence in search markets we model prominence by supposing that the prominent firm will be sampled first by all consumers if there are no systematic quality differences among firms we find that the prominent firm will charge a lower price than its less prominent rivals making a firm prominent will typically lead to higher industry profit but lower consumer surplus and welfare the model is extended by introducing heterogeneous product qualities in which case the firm with the highest quality product has the greatest incentive to become prominent and making it prominent will boost industry profit consumer surplus and welfare

regulating a monopolist with unknown demand the authors analyze the optimal regulatory policy when the firm has better information about demand than the regulator from the outset of their relationship the firm s cost structure is common knowledge but monitoring of output is prohibitively costly the authors find that when marginal production costs increase with output the firm command s no rents from its private information and the efficient price is established for each realization of demand in contrast with declining marginal costs the same price is established by the regulator for all demand realizations and the firm s rents can be substantial overall major qualitative differences in the optimal regulatory policy arise when the firm s private information concerns demand rather than costs copyright 1988 by american economic association

using markets to allocate pollution permits and other scarce resource rights under limited information abstract we consider the design of government policy to ration such scarce resources as water or pollution permits in the presence of limited information when government policy is formulated some informed agents e g established public utilities know how highly they value the resource other uninformed agents e g potential independent power producers only learn their valuations at some later date the government allows uninformed agents to trade the resource rights they receive on a competitive market informed agents may or may not have the same privilege the optimal initial distribution of resource rights differs significantly according to whether informed agents can trade the rights they receive

incentives for conservation and quality improvement by public utilities the author examines the design of incentive programs to motivate regulated utilities to supply both basic service e g electricity supply local telephone service and service enhancements e g energy conservation services improved clarity and speed of voice communication the optimal regulatory programs are shown to vary greatly depending upon the information available to the regulator the price of the basic service may optimally be distorted above or below marginal cost to better motivate the supply of the service enhancement policy prescriptions are compared with current programs and proposals to promote energy conservation 35 refs 2 figs

true monopolistic competition as a result of imperfect information the paper restates hart s 1985a 1985b definition of large group monopolistic competition distinguishes it from oligopolistic competition and raises the question of whether there are reasonable circumstances that give rise to true monopolistic competition as defined the purpose is to show that consumers imperfect information may create conditions that will turn an otherwise oligopolistic market into a truly monopolistically competitive one