reserve prices without commitment abstract when potential bidders in an auction have to incur a cost to prepare their bids and thus to learn their valuations imposing a reserve price and announcing that in case no bid is submitted there will be another auction without a reserve price is both revenue and welfare improving reserve prices that induce less than maximum entry in the first auction may be optimal also entry fees are not necessarily better instruments than reserve prices journal of economic literatureclassification number d44

informational externalities strategic delay and optimal investment subsidies this paper examines optimal government policy when private investment generates information but investors cannot internalize the informational value their actions have to others equilibrium exhibits inefficient delay as investors adopt a wait and see approach the government can alter incentives via an investment subsidy but complications arise since future subsidies may induce investors to disregard current policy initiatives the paper shows that the government achieves its desired outcome only when the the investment subsidy is financed by a non distortionary lump sum tax when taxation is distortionary the government faces a time inconsistency problem that may prevent effective policy ce texte examine la politique optimale du gouvernement quand l investissement prive engendre de l information mais que les investisseurs ne peuvent pas internaliser la valeur informationnelle que leurs actions ont sur les autres l equilibre est marque par des delais inefficaces a proportion que les investisseurs adoptent une attitude attendre pour voir le gouvernement peut modifier les incitations en creant une subvention a l investissement mais des complications sont possibles puisque des subventions possibles dans l avenir peuvent amener les investisseurs a ne pas se prevaloir des initiatives mises de l avant par la politique courante le texte montre que le gouvernement atteint le resultat desire seulement quand la subvention a l investissement est finance par une taxe forfaitaire non distorsionnante quand la taxe cree des distorsions le gouvernement fait face a un probleme d inconsistance dans le temps qui empeche que la politique soit effective

delay and cycles when the profitability of investment depends on the general level of economic activity entrepreneurs have an incentive to delay investments during a recession endogenous delay thus prolongs the recovery from a recession and heightens the effect of the boom this paper describes a dynamic model that exhibits both delay and cycles and develops methods for analysing the role of delay in propogating business cycles a number of interesting characteristics of the cycle are revealed first the effect of delay is asymmetric it lengthens the recovery but not the downturn second delay can increase the amplitude and typically reduces the frequency of the cycle third it can reduce the average level of activity but it achieves this effect by prolonging the recession rather than by reducing the amplitude of the cycle the welfare effects of delay are ambiguous however

a class of differential demand systems abstract the rotterdam almost ideal demand system cbs and nbr models constitute a class of differential demand systems they correspond to alternative assumptions made concerning the constancy of certain parameters this paper discusses the restrictions that they impose on the evolution of demand elasticities over time

learning and capacity expansion under demand uncertainty a competitive dynamic model of entry into a new industry is set up and both its positive and normative aspects are studied the main assumptions are that entry is sequential that it occurs under imperfect information on the size of the market and that better information becomes available as time goes on the gradual improvement in information is due to the fact that later waves of entrants are able to observe the profitability of earlier entrants the major results reported here under suitable restrictions are that the equilibrium rate of entry is monotonically decreasing over time and that at any given point in time it is smaller than the socially optimal one when a new market opens as a result of a product being newly invented for instance or when an existing market starts to expand uncertainty with respect to its size is likely to prevail as a result of this uncertainty entry of firms into such markets typically will occur in waves some firms will enter initially while others will wait to see the consequences of that initial entry if the experience of early entrants is favourable entry will continue otherwise entry will cease hence with the introduction of a new product two phases are associated the growth phase typified by positive operating profits for existing firms and expansion of productive capacity due to entry of new firms and the mature phase typified by erosion of profits and fixed total productive capacity empiricists estimating the time pattern of investments during the growth phase have found an s shaped diffusion curve see mansfield 1986 and gort and klepper 1982 the purpose of the present paper is to theoretically characterize these time patterns and to investigate their welfare properties any attempt to model the type of entry described above must account for differences in both entry dates and resultant earnings in other words the theory must explain why the realized earnings of different cohorts of firms are not equal often such ex post differences are reconciled by assuming heterogeneity with respect to some latent underlying characteristic managerial ability for instance and attributing differences in earnings to differences in that characteristic in this paper instead earning differentials are attributable to luck only ex ante all firms are technologically identical and equally capable of forecasting market prospects and rationally acting upon those forecasts ex post some firms turn out to have entered at the right time and are for that reason more profitable the model developed in this paper analyzes a parametric example of a sequential entry problem in which the uncertainty over market size is gradually resolved over time in a bayesian setting in an environment of perfect competition and constant returns toscale a free entry equilibrium concept is introduced and the aggregate implications of the time path of investments are derived i then compare this actual time path to the optimum this comparison is interesting because the equilibrium is analysed under the

differential consumer demand systems it is shown in this paper that several well known systems like the rotterdam model and the almost ideal demand system can be seen as different parametrizations of the budget share differential equation using a third parametrization a new system called the cbs system is developed and discussed special attention is given to the relative price version of the system and in particular to the special case of preference independence some estimates for the netherlands based on time series for 1953 1981 using various approaches are presented

revisiting aggregate u s meat demand with a bayesian averaging of classical estimates approach do we need a more general theory although meat demand is one of the most studied issues in agricultural economics our understanding of this phenomenon has been hampered by valid concerns about model specification uncertainty this article revisits the need for more general theories of aggregate u s meat demand using a bayesian averaging of classical estimates approach we draw comprehensive inferences over 1 048 576 demand systems we find very little evidence supporting the need for more general theories that include demand determinants beyond prices and expenditures we find strong evidence in support of symmetry and negativity but strong evidence against homogeneity which is consistent with other research copyright 2008 oxford university press

mass layoffs and unemployment abstract mass layoffs give rise to groups of unemployed workers who possess similar characteristics and therefore may learn from one another s experience searching for a new job two factors lead them to exert too little effort in equilibrium the first is an information externality searchers fail to take into account the value of their experience to others the second is an incentive to free ride each worker would like others to experiment and reveal information concerning the location of productive jobs together these forces imply that in equilibrium the natural rate of unemployment is too high

an equilibrium analysis of information aggregation and fluctuations in markets with discrete decisions abstract this paper shows how the interaction between decentralized information gathering and discreteness of investment decisions at the individual level can generate random fluctuations in aggregate investment that involve occasionally large allocation errors this interaction is illustrated in a model in which private information is costly to acquire and prices reveal information the unique rational expectations equilibrium outcome of the model is shown to always be noisy and characterized by investment levels which may be high simply because uninformed investors are buying under the impression that the high price is a signal of good investment opportunities

sectoral shifts and cyclical unemployment a substantial fraction of cyclical unemployment is better characterized as fluctuations of the frictional or natural rate than as deviations from some relatively stable natural rate shifts of employment demand between sectors of the economy necessitate continuous labor reallocation since it takes time for workers to find new jobs some unemployment is unavoidable this paper presents evidence that most of the unemployment fluctuations of the seventies unlike those in the sixties were induced by unusual structural shifts within the u s economy simple time series models of layoffs and unemployment are constructed that include a measure of structural shifts within the labor market these models are estimated and a derived natural rate series is constructed

growth under uncertainty with experimentation abstract we introduce bayesian learning into a stochastic growth model and study the effect of experimentation on the optimal level of the investment decision and on the amount of information gathering when more investment produces more information experimentation can push towards a lower level of investment thus reducing information acquisition symmetrically when more investment reduces information experimentation can increase investment and again decrease information gathering these results run contrary to intuitions generated by the standard literature on experimentation

alternative common value auction procedures revenue comparisons with free entry the logic of revenue comparisons for different types of common value auctions is substantially altered if the number of participants rather than being fixed responds endogenously to the expected profitability from participating in a thoroughly symmetric model a seller may prefer that competition be indirect an auction procedure in which fewer participants are needed to drive the expected profitability from participating down to the level obtainable in other auctions in the economy can attain higher expected revenue if a sale is sufficiently likely this insight allows a complete revenue ranking of standard auction procedures with endogenous entry

free entry and social inefficiency our goal is to provide a simple yet general exposition of the conditions under which the number of entrants in a free entry equilibrium is excessive insufficient or optimal our analysis compares the number of firms that enter a market when there is free entry with the number that would be desired by a social planner who is unable to control the behavior of firms once they are in the market that is we consider the second best problem of choosing the welfare maximizing number of firms while we take as given their noncompetitive behavior after entry we demonstrate that the crucial conditions for establishing the presence of an entry bias can be stated quite simply in terms of the outcome of the postentry game played by entrants in contrast to previous work we do not need to model this postentry game explicitly

experimentation and competition abstract this paper examines the effect of competition on firms efforts to experiment and learn about market demand consumers are assumed to know prices only at sellers they have actually visited but must bear search costs to find the prices of other sellers under these conditions we show that firms incentives to experiment are diluted by comparison with the monopoly case and that this effect is stronger the smaller the search cost the learning environment we portray gives rise to several time paths which have been empirically documented including penetration pricing cream skimming and cyclical pricing journal of economic literature classification numbers c73 d43 d83

price dispersion and learning in a dynamic differentiated goods duopoly we study the evolution of prices set by duopolists who are uncertain about the perceived degree of product differentiation customers sometimes view the products as close substitutes sometimes as highly differentiated as the informativeness of the quantities sold increases with the price differential there is scope for active learning by firms when information has low value to the firms they charge the same price as would be set by myopic players and there is no price dispersion when firms value information more highly on the other hand they actively learn by creating price dispersion such price dispersion arises in a cyclical fashion and is most likely to be observed when the firms environment changes sufficiently often but not too frequently firms payoffs are higher when they use correlated pricing strategies contrary to what one might expect such coordination need not hurt consumers provided they are sufficiently impatient

irreversible investment and strategic interaction this paper introduces an aggregate demand externality into a model of irreversible invest ment the central result of the paper establishes the mechanism in which increases in uncer tainty can lead to suboptimal recessions these inefficient outcomes occur even if agents are allowed to coordinate to the best possible equilibria the result is driven by the external effects of firms investment decisions how can a small increase in uncertainty cause a large suboptimal drop in output this paper studies this question through a simple model of investment coupled with aggregate demand externalities the idea that economic uncer tainty is high in times preceding and during recessions is very intuitive how ever a study of its causal role for suboptimal business cycles is hampered by the absence of any rigorous transmission mechanism we are proposing one such mechanism and while our model is too stylized to allow for any direct empirical test we hope that it is the first step towards the creation of robust models with testable implications our analysis takes place in an uncertain environment where firms must choose a level of irreversible investment the literature on this problem is well developed with the fairly robust result that either an increase in uncertainty or an increase in the quality of information to arrive in the future will cause

on optimal reservation prices in auctions the theory of auction design examines how various factors affect the outcome of an auction most of the existing literature focuses on how varying the amount of information available to each bidder affects the bid taker s expected revenue when all other factors remain constant this paper studies how the bid taker s expected revenue varies with changes in the auction format when such changes affect the number of bidders and in turn the bidders maximum value for the object being sold specifically we examine how varying the reservation price or screening level affects the bid taker s expected revenue though its effect on the number of bidders for two simple examples the losses associated with a reduced number of bidders outweighs any benefits that nontrivial reservation prices might have had in models with an exogonously set number of bidders

sectoral shocks learning and aggregate fluctuations we present a model in which sectoral shocks have aggregate consequences the model relies on irreversible investment and imperfect information to slow the adjustment of expanding industries we show that this gradual expansion is sub optimal

boom and bust patterns in the adoption of financial innovations we develop a dynamic model of the adoption of financial innovations each period firms decide whether or not to adopt an innovation of uncertain value and the profitability of each period s adoptions reveals information about the innovation s value we show that characteristics of financial innovation waves cited by critics as evidence of irrational excess are in fact consistent with fully rational behavior we also show that social welfare is enhanced when more firms adopt innovations of questionable value and that financial intermediaries base an incentive to encourage such adoption article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

advertising and us alcoholic beverage demand system wide estimates the effects of advertising on consumption of alcoholic beverages in the us are analysed the goal is to obtain evidence on the importance of advertising at the level of beverage demand beer wine spirits and for total consumption of alcohol per capita gallons of ethanol a three equation conditional demand system is estimated that includes own and cros beverage advertising as explanatory variables four models of the differential demand system are estimated including the rotterdam aid cbs and nbr models using annual us data for the period 1964 90 on beverage consumption prices expednitures and real advertising estimates are obtained of the complete matrix of own and cross elascities for each beverage price and advertising at the beverage level the results indicate a positive butr very small effect of advertising on beverage consumption with most of the impact due to wine advertising and non due to beer advertising there is no efect of advertising in the composite demand function for al

on a possible benefit to bid takers from using multi stage auctions each year multi stage auctions of one form or another sell or let billions of dollars worth of goods and contracts yet despite the significance of such auctions the existing theory of auctions and competitive bidding fails to explain why a bid taker might prefer a multi stage auction to a possibly simpler single stage mechanism in fact the existing theory tends to overlook multi stage mechanisms altogether this paper takes a first step in correcting that omission we start with several illustrations of what we will define to be multi stage auctions all the illustrated auctions allow bidders to acquire information or more generally to increase the amount of resources committed to bidding in stages we conjecture that allowing such a sequential commitment of resources could result in a more efficient auction than if bidders had no chance to adjust their commitments an analytic example illustrates and documents the benefits to the bid taker from using a multi stage auction in the example bidders acquire costly information in stages a bidder may stop acquiring additional information as soon as further participation in the auction would no longer increase his expected net profit the resulting auction generates significantly more expected revenue for the bid taker than if the bidders all had to acquire the same amount of information

entry and exit under demand uncertainty abstract this paper presents a dynamic model of entry and exit in competitive markets with demand uncertainty and bayesian learning there is a unique equilibrium path characterized by a pair of simple zero expected profit equations

investment timing and learning externalities abstract we study a duopoly model of investment in which each player learns about the quality of a common value project by observing some public background information and possibly the experience of his rival investment costs are private information and the background signal takes the form of a poisson process conditional on the quality of the project being low the resulting attrition game has a unique symmetric equilibrium which depends on initial public beliefs we determine the impact of changes in the cost and signal distributions on investment timing and how equilibrium is affected when a first mover advantage is introduced

taking the road less traveled by does conversation eradicate pernicious cascades abstract we offer a model in which sequences of individuals often converge upon poor decisions and are prone to fads despite communication of the payoff outcomes from past choices this reflects both direct and indirect action based information externalities in contrast with previous cascades literature cascades here are spontaneously dislodged and in general have a probability less than one of lasting forever furthermore the ability of individuals to communicate can reduce average decision accuracy and welfare

bayesian learning in an infant industry model abstract most analyses of the infant industry argument assume that production early on benefits subsequent production in deterministic fashion this paper presents an alternative framework for evaluating the infant industry argument that focuses on imperfect information as a barrier to entry initial entrants provide information of social value by reducing uncertainty for potential followers about the suitability of local conditions in contrast to earlier work i show that factors that increase the informational barrier to entry may lower the optimal subsidy to the infant industry and that the standard test of the success of infant industry policy is not always valid 1997 elsevier science b v

pareto optima and competitive equilibria with adverse selection and moral hazard this paper explores the extent to which standard general equilibrium analysis of pareto optima and of competitive equilibria can be applied to environments with moral hazard and adverse selection problems allowing for lotteries contracts with random components we first establish that an adverse selection insurance economy a moral hazard insurance economy a signaling economy and a private information labor market economy are all special cases of a simple general structure we then show that techniques for characterizing pareto optimal contracts as solutions to concave programming problems are useful and nice and appear to be broadly applicable allowing for lotteries we show how to characterize the optimal allocations for the adverse selection insurance and labor market economies we then show that standard existence and optimality theorems for competitive equilibria apply in the linear space containing lotteries if agents with characteristics which are distinct and privately observed at the time of initial trading enter the economy wide resource constraints in a homogeneous way other kinds of diversity are not critical for economies with moral hazard which satisfy the homogeneity condition competitive contract markets single out a subset of the optima and thus can be consistent with apparent unemployment and with a random allocation of labor supplied though all households are averse to risk the adverse selection insurance and signaling economies however do not satisfy the homogeneity condition and are difficult to decentralize efficiently with a price system

an exploration into pigou s theory of cycles abstract this paper explores a theory of business cycles in which recessions and booms arise due to difficulties encountered by agents in properly forecasting the economy s future needs in terms of capital the idea has a long history in the macroeconomic literature as reflected by the work of pigou industrial fluctuation macmillan london 1926 the contribution of this paper is twofold first we illustrate the type of general equilibrium structure that can give rise to such phenomena second we examine the extent to which such a model can explain the observed pattern of u s recessions frequency depth without relying on technological regress we argue that such a model offer a framework for understanding elements of both the recent u s recession and of the asia downturns of the late 1990s

an informational externality in a competitive market abstract consider a new competitive market with unknown demand the market price generated by incumbents conveys information that firms including potential entrants use for future decisions yet the incumbents are not rewarded for their assistance suggesting that an inefficiency can exist it has been argued that greater entry generates more information about a new market and should be subsidized a simple model of partial information and learning is developed finding that an informational externality can exist in competitive markets but there may be excessive entry free entry and a public price conditions for competitive market efficiency are conditions for inefficiency

investment as a process of search this paper analyzes optimal capital accumulation in the face of structural uncertainty in which the firm does not fully know its own profit function and can discover it only through further investment it is shown that under structural uncertainty capital accumulation is gradual even when adjustment costs are linear and not convex it is further shown that structural uncertainty creates an incentive to market research the paper also presents an example of structural uncertainty in which an additional price uncertainty has a negative effect on investment contrary to the standard models

business as usual market crashes and wisdom after the fact the authors present a three stage model of market dynamics in the first stage routine behavior tends to keep information of common interest trapped in private hands in the second stage private information reaches a threshold that triggers some agents to alter their behavior these actions release information to the market the final stage involves the market s response to this news as other participants react to the initial departure from routine behavior the authors present an application to industry investment they also outline applications to the international debt crisis to bank runs and to political upheavals copyright 1994 by american economic association

taking one for the team is collective action more responsive to ecological change debate persists around the timing of risk reduction strategies for large scale ecological change for three reasons risks are difficult to predict they involve irreversibilities and they impact multiple jurisdictions the combination of these three factors creates a general class of filterable spatial dynamic externalities fsde in which one person s risk reduction investments reduce or filter undesirable events experienced by others and underestimates the option value placed on being able to respond to new information about the consequences of ecological change by focusing on the optimal intervention decision we illustrate how and when the opposing forces created by an fsde will lead to a divergence in private and collective risk reduction strategies we use bioinvasions as our motivating example the bioinvasion first hits one jurisdiction and that jurisdiction s risk reduction investment reduces the risk faced by all other jurisdiction we find that efforts to internalize the full benefits of risk reduction investments may have unintended consequences on the responsiveness of environmental policy there is a social welfare gain from asking the first jurisdiction to delay a risk reduction investment to internalize the option values of all at risk jurisdictions

the matrix approach to evaluating demand equations as there is a plethora of demand models which one should be used to estimate income and price elasticities the paper sheds light on this important practical problem by developing a matrix approach to simulating mas demand equations to analyse their performance under idealized circumstances artificial data on the dependent variable are generated by one model and these are then used for the estimation of another model as an illustrative application using four popular models a 4 4 matrix is generated which gives all pair wise comparisons the performance of the models is then evaluated on the basis of the quality of the income and own price elasticity estimates

understanding investment irreversibility in general equilibrium miquel faig i introduction many forms of investment are irreversible a growing body of literature 1 has shown that irreversibility is important for firms investment decisions under uncertainty however we still know little about the consequences of investment irreversibility for the economy as a whole that is in general equilibrium learning about these consequences is not only important for a better understanding of capital accumulation it is also important for an understanding of the information that asset returns provide about the business cycle in fact recent papers by boldrin christiano and fisher 1995 beaudry and guay 1996 and jermann 1998 convincingly argue that impediments to the reallocation of capital are crucial to generate realistic dynamics for asset returns thus understanding the general equilibrium consequences of investment irreversibility is important to the theories of economic growth the business cycle and asset pricing in this article i advance an analytically tractable model to explore the consequences of investment irreversibility in general equilibrium the main contribution of this model to the existing literature is analytical tractability analytical results from the literature dealing with investment irreversibility in general equilibrium are scarce and mainly limited to general properties such as existence of solutions as in sargent 1980 and olson 1989 fortunately thanks to numerical simulations we know some of the effects of investment irreversibility in general equilibrium for example using an extension to the neoclassical growth model coleman 1997 documents that irreversibility significantly affects interest rates and it may increase aggregate investment even when no constraints are binding 2 in contrast firms behavioral analyses and the related competitive equilibrium model by leahy 1993 show that irreversibility typically discourages capital creation the model advanced in this paper helps to understand and to formalize why such contrast exists the model of this article extends the endogenous growth model found in barro 1990 the four main assumptions of the model are the following all production processes yield the same output which can be consumed or invested in many types of capital all factors of production are a type of capital the aggregate production function yields constant returns to scale preferences are homothetic and modeled along the lines of epstein and zin 1989 these preferences include as a special case the standard isoelastic time additive preferences but they allow to distinguish between the inter temporal elasticity of substitution and the inverse of the coefficient of relative risk aversion these two parameters play important and distinct roles in the analysis to attain strong analytical results the model in this article has to adopt the restrictive assumption that all factors of production are a form of capital however the model remains quite flexible to capture important elements of reality the model allows for many types of capital so some of them can be interpreted as human capital also the model allows great flexibility on the stochastic shocks affecting the production possibilities of the economy finally the model allows for the coexistence of irreversible and flexible types of capital with or without complementarities between them this diversity of capital types is important to generate endogenous interest rates and endogenous marginal products of capital also capital diversity allows for strongly binding irreversibility constraints even with positive gross investment as it has always been the model reveals that in general equilibrium there are three effects of irreversibility on aggregate investment the first is the obvious direct effect of preventing capital destruction in periods one may wish to consume part of the capital stock

miracle on sixth avenue information externalities and search after a long dormant period lower sixth avenue in new york has undergone a rapid revitalisation we show that a simple search theoretic model with information spillovers can explain both the period of underuse and the rapid turnaround the model reduces to a simple equation which allows us to do comparative statics on the duration of vacancies we show how the solution reacts to changes in market structure and changes in search technology the model is suggestive of difficulties that may occur in many markets in which there are changes over time in the optimal use of resources at one time lower sixth avenue was one of the most fashionable retail centres in manhattan but the area collapsed as a retail centre when the affluent moved further uptown and to the suburbs today sixth avenue is in the midst of a rapid turnaround as reported in the sunday new york times by claudia

incomplete information high low bidding and public information in first price auctions high low bidding refers to auctions of a series of objects where for a subset of the auctioned objects one of two buyers bids high on some objects and low on others while the other buyer does the reverse this paper shows that high low bidding does not imply collusive behavior among buyers in particular through a formal modeling of a noncooperative game of information acquisition and bidding decisions it shows that high low bidding can be obtained the paper also demonstrates that if the cost of information to a seller is less than the equilibrium joint expected information cost of the buyers then it pays the seller to provide public information finally if the provision of public information is not feasible but a seller can know whether buyers have acquired information then it pays the seller to make known to the buyers and to pursue a policy that just prior to the start of an auction the seller will announce which buyer has acquired information