investment and market structure in industries with congestion we analyze investment incentives and market structure under oligopoly competition in industries with congestion effects our results are particularly focused on models inspired by modern technology based services such as telecommunications and computing services we consider situations where firms compete by simultaneously choosing prices and investments increasing investment reduces the congestion disutility experienced by consumers we define a notion of returns to investment according to which congestion models inspired by delay exhibit increasing returns whereas loss models exhibit nonincreasing returns for a broad range of models with nonincreasing returns to investment we characterize and establish uniqueness of pure strategy nash equilibrium we also provide conditions for existence of pure strategy nash equilibrium we extend our analysis to a model in which firms must additionally decide whether to enter the industry our theoretical results contribute to the basic understanding of competition in service industries and yield insight into business and policy considerations

credit and inflation under borrowerʼs lack of commitment here we investigate the existence of credit in a cash in advance economy where there are complete markets but for the fact that agents cannot commit to repay their debts defectors are banned from the credit market but they can use money balances for saving purposes without uncertainty deflation crowds out credit completely the equilibrium allocation however is efficient if the government deflates at the time preference rate efficiency can also be restored with positive inflation for any non negative inflation rate below the optimal level the volume of credit and the real interest rate increase with inflation our results hold when idiosyncratic uncertainty is introduced and households are sufficiently impatient but in one instance efficiency cannot be restored if the deflation rate is nearby the rate of time preference our numerical examples suggest that the optimal inflation rate is not too large for reasonable levels of patience and risk aversion finally we present a framework where the use of money arises endogenously and show that it is tantamount to our cash in advance framework our results hold in this modified environment

heterogeneity redistribution and the friedman rule we study monetary models with nondegenerate stationary distributions of money holdings we find that the friedman rule does not typically maximize ex post social welfare an increase in the rate of growth of the money supply has two effects the standard distortionary or rate of return effect makes money a less desirable asset for all moneyholders a second redistributive effect creates a transfer from one type of agent to the other an increase in the rate of growth of money away from the friedman rule can produce a rate of return effect that dominates the standard effect

money credit and banking in monetary models where agents are subject to trading shocks there is typically an ex post inefficiency since some agents are holding idle balances while others are cash constrained this problem creates a role for financial intermediaries such as banks who accept nominal deposits and make nominal loans in general financial intermediation improves the allocation the gains in welfare come from the payment of interest on deposits and not from relaxing borrowers liquidity constraints we also demonstrate that when credit rationing occurs increasing the rate of inflation can be welfare improving

airport charges and capacity expansion effects of concessions and privatization abstract this paper examines the decisions on airport charges and capacity expansion made by airports with different objectives we find that allowing an airport to have profitable concession operations may be more welfare improving than the alternative of depriving the airport of all profits from concession operations furthermore the airport charge of a social welfare maximizing airport would be lower than that of a budget constrained public airport which in turn would be lower than that of a privatized airport pursuing profit maximization we also show that a constrained public airport would add capacity later than a social welfare maximizing airport whilst a privatized airport would add capacity later still given that constrained public airports represent the second best situation the capacity decisions of privatized airports would be socially suboptimal

monetary policy and distribution a segmented markets model of monetary policy is constructed in which a novel feature is goods market segmentation and its relationship to conventional asset market segmentation the implications of the model for the response of prices interest rates consumption labor supply and output to monetary policy are determined as well optimal monetary policy is studied as are the costs of inflation the model features persistent nonneutralities of money relative price effects of increases in the money supply persistent liquidity effects and a negative fisher effect from a money supply increase a friedman rule is in general suboptimal

bubbles and self enforcing debt we characterize equilibria with endogenous debt constraints for a general equilibrium economy with limited commitment in which the only consequence of default is losing the ability to borrow in future periods first we show that equilibrium debt limits must satisfy a simple condition that allows agents to exactly roll over existing debt period by period second we provide an equivalence result whereby the resulting set of equilibrium allocations with self enforcing private debt is equivalent to the allocations that are sustained with unbacked public debt or rational bubbles in contrast to the classic result by bulow and rogoff 1989a positive levels of debt are sustainable in our environment because the interest rate is sufficiently low to provide repayment incentives

it pays to be different endogenous heterogeneity of firms in an oligopoly abstract heterogeneous firms can be supported by familiar conditions of technology and demand in a two stage duopoly game firms choose technologies simultaneously in stage i from a continuous technology set in stage ii once technological commitments have been made firms choose quantities and the equilibrium price is determined if the technology set is insufficiently convex firms choose only the extreme production technologies in some cases they choose the same technology in others they choose different technologies when compared to socially optimal industry structures equilibria tend to have too little heterogeneity uncertainty about demand or costs favors the emergence of heterogeneous firms

the distribution of money balances and the nonneutrality of money recent monetary models with explicit microfoundations are made tractable by assuming that agents have access to centralized markets after one round of decentralized trade given quasi linear preferences this makes the distribution of money degenerate which keeps the models simple but precludes the discussion of distributional effects of monetary policy we generalize these models by assuming two rounds of trade before agents can readjust their money holdings to study a range of new distributional effects analytically we show that unexpected symmetric lump sum money injections may increase short run output and welfare whereas asymmetric injections may increase long run output and welfare

liquidity constrained markets versus debt constrained markets this paper compares two different models in a common environment the first model has liquidity constraints in that consumers save a single asset that they cannot sell short the second model has debt constraints in that consumers cannot borrow so much that they would want to default but is otherwise a standard complete markets model both models share the features that individuals are unable to completely insure against idiosyncratic shocks and that interest rates are lower than subjective discount rates in a stochastic environment the two models have quite different dynamic properties with the debt constrained model exhibiting simple stochastic steady states while the liquidity constrained model has greater persistence of shocks

bertrand competition and cournot outcomes further results the model of kreps and scheinkman where firms choose capacities and then compete in price is extended to oligopoly further capacity is an imperfect commitment device firms can produce beyond capacities at an additional unit cost when is larger than the cournot price the cournot outcome obtains in the unique subgame perfect equilibrium when decreases from the cournot price towards zero the whole range of prices from cournot to bertrand is obtained in equilibrium

consumer bankruptcy a fresh start consumer bankruptcy provides partial insurance against bad luck but by driving up interest rates makes life cycle smoothing more difficult we argue that to assess this trade off one needs a quantitative model of consumer bankruptcy with three key features life cycle component idiosyncratic earnings uncertainty and expense uncertainty exogenous negative shocks to household balance sheets we find that transitory and persistent earnings shocks have very different implications for evaluating bankruptcy rules more persistent shocks make the bankruptcy option more desirable larger transitory shocks have the opposite effect our findings suggest the current us bankruptcy system may be desirable for reasonable parameter values jel d14 d91 k35

optimal monetary policy what we know and what we don t know in this article i examine the current state of knowledge about optimal monetary policy i distinguish between two literatures basic and applied the basic literature is explicit about the frictions that generate a positive value for money and make it socially beneficial the applied literature is not i describe the recent lessons about monetary policy that we have learned from each literature and discuss how the two distinct approaches may be usefully combined

second best congestion pricing the case of an untolled alternative abstract this paper deals with second best one route congestion pricing in case of an untolled alternative using a two link network simulation model the effects of various demand and cost parameters on the relative efficiency of one route tolling are analyzed it is investigated whether the existence of costs of congestion charging may be a reason for one route tolling to be more overall efficient than two route tolling finally the efficiency of revenue maximizing one route and two route tolling is discussed

money as a mechanism in a bewley economy we study what features an economic environment might possess such that it would be pareto ecient for the exchange of goods in that environment to be conducted on spot markets where those goods trade for money we prove a conjecture that is essentially due to bewley 1980 1983 the gist is that monetary spot trading is nearly ecient ex ante in an environment where very patient agents can accumulate large enough money stocks to be completely self insured we also study examples where a nonmonetary mechanism is preferred ex ante to any monetary mechanism at least when the comparison is restricted to stationary equilibria and where an inflationary monetary mechanism is preferred ex ante to a laissez faire or deflationary monetary mechanism in an environment with impatient agents j e l classification e31 e42

international business cycles with endogenous incomplete markets backus kehoe and kydland 1992 baxter and crucini 1995 and stockman and tesar 1995 find two major discrepancies between standard international business cycle models with complete markets and the data in the models cross country correlations are much higher for consumption than for output while in the data the opposite is true and cross country correlations of employment and investment are negative while in the data they are positive this paper introduces a friction into a standard model that helps resolve these anomalies the friction is that international loans are imperfectly enforceable any country can renege on its debts and suffer the consequences for future borrowing to solve for equilibrium in this economy with endogenous incomplete markets the methods of marcet and marimon 1999 are extended incorporating the friction helps resolve the anomalies more than does exogenously restricting the assets that can be traded

timing of investments in oligopoly under uncertainty a framework for numerical analysis abstract we present a modeling framework for the analysis of investments in an oligopoly market for a homogenous commodity the demand evolves stochastically and the firms carry out investment projects in order to adjust their production cost functions or production capacities the model is formulated as a discrete time state space game where the firms use feedback strategies the firms are assumed to move sequentially to ensure a unique markov perfect nash equilibrium once the equilibrium has been solved monte carlo simulation is used to form probability distributions for the firms cash flow patterns and accomplished investments such information can be used to value firms operating in an oligopoly market an example of the model is given in a duopoly market the example illustrates the trade off between the value of flexibility and economies of scale under competitive interaction

capacity expansion and the size of plants scale economies in industrial plants confer a tradeoff on firms between the capacity of production facilities and the average cost of production this tradeoff is central to firms capacity expansion decisions in growing industries this article imbeds the cost versus capacity tradeoff in an investment timing game and explores the properties of equilibrium capacity expansion in growing industries with free entry some of the results are analytical and others are based on numerical examples using a particular class of demand functions equilibrium capacity expansion is suboptimal from a social point of view but it involves zero profits small plants with high unit costs can coexist in a rent dissipating equilibrium with large plants with low unit costs small plants sometimes precede and at other times follow the installation of large plants as the industry evolves along the equilibrium path

an empirical analysis of lumpy investment the case of us petroleum refining industry this paper employs five econometric models to examine lumpy investment and investigates the investment behavior of the us petroleum refining industry firms in the industry are classified into three groups by their size all three groups show zero investment disinvestment and investment in accordance with economic conditions the analysis finds the minimum amount of investment and disinvestment for each group which suggests that the size of fixed costs of investment is substantial regardless of firm size however small firms adjust capital stock more slowly than medium or large firms the analysis also suggests the existence of a convex adjustment cost

money and asset prices in a cash in advance economy an asset pricing model with money introduced via a cash in advance constraint is presented the monetary velocity is variable hence money demand does not obey the trivial quantity equation the effects of disturbances in output and money growth on real balances the price level and interest rates are examined monetary policy has effects on real asset prices the fisher relation and the premium on nominal bonds are discussed the precise role of the timing of information and transactions for properties of price levels and interest rates are clarified

money and dynamic credit arrangements with private information abstract we construct a model with private information in which consumers write dynamic contracts with financial intermediaries a role for money arises due to random limited participation of consumers in the financial market without defection constraints a friedman rule is optimal the mean and variability of wealth tend to fall with inflation in the steady state and the welfare effects of inflation are very small with defection constraints the effects of inflation on the distribution of welfare and consumption are large but the effect on average welfare is still small the relaxation of defection constraints resulting from higher inflation can cause a substantial increase in the real interest rate journal of economic literature classification numbers d8 e4 g2

optimal monetary policy in an economy with incomplete markets and idiosyncratic risk abstract this study investigates an incomplete markets economy in which the saving behavior of a continuum of infinitely lived agents is influenced by precautionary saving motives and borrowing constraints agents can use two types of assets interest bearing ious and money to smooth consumption money is valued because of a timing friction in the bond market in particular the bond market closes before agents observe their idiosyncratic productivity shock i find that the friedman rule is not optimal for this economy the results indicate that the optimal allocation has a rate of inflation of 10 and a positive amount of private credit held by the government a positive inflation rate transfers resources from agents with big endowments to those holding bonds which improves risk sharing and therefore welfare however for higher rates of inflation agents economize on money holdings offsetting the insurance effects and causing a reduction in welfare furthermore higher rates of inflation discourage agents from borrowing and the endogenous lower bound on bond holdings is higher than the exogenous borrowing limit high rates of inflation therefore exacerbate frictions in the bond market

competitive equilibria with limited enforcement we show how to decentralize constrained efficient allocations that arise from enforcement constraints between sovereign nations in a pure exchange economy these allocations can be decentralized with private agents acting competitively and taking as given government default decisions on foreign debt in an economy with capital these allocations can be decentralized if the government can tax capital income as well as default on foreign debt the tax on capital income is needed to make private agents internalize a subtle externality the decisions of the government can arise as an equilibrium of a dynamic game between governments

prices capacities and service levels in a congestible bertrand duopoly we study the duopolistic interaction between congestible facilities that supply perfect substitutes and that make sequential decisions on capacities and prices the consumers time cost of accessing or using a facility is determined by the volume capacity ratio we analyze duopoly prices capacities and service quality defined as the inverse of time costs of using the facility and compare the results to monopoly and first best outcomes findings include the following first while price competition between duopolists is beneficial for consumers introducing capacity competition is harmful the duopolist offers lower service quality than the monopolist who does provide the socially optimal quality level second higher marginal costs of capacity may increase profits third asymmetric nash equilibria may result even when firms are ex ante identical more specifically when capacity is cheap or demand is relatively inelastic the only stable equilibria are asymmetric in such an equilibrium the large facility provides high quality at a high price and the smaller facility offers lower quality at lower prices in other words there is endogenous product differentiation by ex ante identical firms

anticipated inflation and the capital stock in a cash in advance economy abstract an economy is constructed in which the steady state capital stock is inversely related to the rate of inflation as a result that is directly opposite the usual conclusion

a unified framework for monetary theory and policy analysis search theoretic models of monetary exchange are based on explicit descriptions of the frictions that make money essential however tractable versions of these models typically make strong assumptions that render them ill suited for monetary policy analysis we propose a new framework based on explicit micro foundations within which macro policy can be studied the framework is analytically tractable and easily quantifiable we calibrate the model to standard observations and use it to measure the cost of inflation we find that going from 10 percent to 0 percent inflation is worth between 3 and 5 percent of consumption much higher than previous estimates

bertrand competition and cournot outcomes a correction abstract we received independent comments from dan kovenock and luis ubeda regarding proofs of lemma 1 and theorem 1 in boccard and wauthy econ lett 68 2002 279 hereafter bw claim 4 is indeed poorly stated and proved while in the proof of theorem 1 payoffs for the price subgame are incorrectly derived we apologize for these shortcomings fortunately the spirit of the proof is not altered by slightly weakening the scope of the analysis for capacity choice from mixed strategies into pure ones we are able to shorten the proof that is presented hereafter

efficient allocations with hidden income and hidden storage we consider an environment in which individuals receive income shocks that are unobservable to others and can privately store resources we provide a simple characterization of the unique efficient allocation of consumption in cases in which the rate of return on storage is sufficiently high or alternatively in which the worst possible outcome is sufficiently dire we show that unlike in environments without unobservable storage the symmetric efficient allocation of consumption is decentralizable through a competitive asset market in which individuals trade riskfree bonds among themselves in this paper we consider an environment in which individuals have random income and can accumulate assets through a storage technology their income realizations and their asset position are private information given these informational frictions we provide a simple characterization of the unique efficient allocation of consumption in cases in which the rate of return on storage is sufficiently high or alternatively in which the worst possible outcome is sufficiently dire we show that the symmetric efficient allocation of consumption is decentralizable through a competitive asset market in which individuals trade risk free bonds among themselves there is a large prior literature which examines the characteristics of efficient risksharing in dynamic settings in the presence of private information unlike our paper this literature generally finds that efficient allocations do not coincide with the equilibrium allocations of any economy with a competitive bond market see atkeson and lucas 1992 in particular the key difference between our paper and these preceding ones is that the earlier literature assumes either that agents cannot accumulate resources over time or that if they can this accumulation is observable in contrast we assume that both agents incomes and their stored resources are private information it is this combination of assumptions that leads to our result our findings are reminiscent of allen s 1985 he considers a dynamic principalagent relationship in which the agent is risk averse and has hidden stochastic income the

the risk free rate in heterogeneous agent incomplete insurance economies abstract why has the average real risk free interest rate been less than one percent the question is motivated by the failure of a class of calibrated representative agent economies to explain the average return to equity and risk free debt i construct an economy where agents experience uninsurable idiosyncratic endowment shocks and smooth consumption by holding a risk free asset i calibrate the economy and characterize equilibria computationally with a borrowing constraint of one year s income the resulting risk free rate is more than one percent below the rate in the comparable representative agent economy

heterogeneous firms and the organization of production firms in the same industry exhibit systematic differences in the organization of production and the structure of employment entrepreneurial ability is the specific scarce input that limits the size of a firm this input must be allocated to two activities coordinating production and monitoring workers able entrepreneurs can convert calendar time into larger supplies of coordinating effort that enable them to assemble large firms greater ability implies a higher shadow price of time which increases the implicit costs of monitoring a dispersion of entrepreneurial abilities generates an equilibrium size distribution of firms differences in monitoring costs affect the choice of worker productivities the design of products and the organization of production the monitoring cost hypothesis advanced in this paper goes a long way in explaining the equilibrium of an industry containing heterogeneous firms that differ in size and behavior

debt constrained asset markets we develop a theory of general equilibrium with endogenous debt limits in the form of individual rationality constraints similar to those in the dynamic consistency literature if an agent defaults on a contract he can be excluded from future contingent claims markets trading and can have his assets seized he cannot be excluded from spot markets trading however and he has some private endowments that cannot be seized all information is publicly held and common knowledge and there is a complete set of contingent claims markets since there is complete information an agent cannot enter into a contract in which he would have an incentive to default in some state in general there is only partial insurance variations in consumption may be imperfectly correlated across agents interest rates may be lower than they would be without constraints and equilibria may be pareto ranked

comparing cournot and bertrand in a homogeneous product market abstract this paper examines some general notions relating to the comparison of cournot and bertrand equilibrium outcomes results obtained by vives in this connection are reconsidered in a homogeneous product market and it is shown that these results are sensitive to the market sharing rules it is found that the results are always true under those market sharing rules which have the property of including the competitive equilibrium in the set of bertrand equilibria for example the capacity sharing rule if however the sharing rule does not have this property for example the equal sharing rule then the results referred to above may not hold when costs are asymmetric journal of economic literatureclassification numbers l13

outside versus inside bonds a modigliani miller type result for liquidity constrained economies when agents are liquidity constrained two options exist sell assets or borrow we compare the allocations arising in two economies in one agents can sell government outside bonds and in the other they can borrow by issuing inside bonds all transactions are voluntary implying no taxation or forced redemption of private debt we show that any allocation in the economy with inside bonds can be replicated in the economy with outside bonds but that the converse is not true however the optimal policy in each economy makes the allocations equivalent

asset trading mechanisms and expansionary policy abstract previous authors have argued that the otimal monetary policy is contractionary if buyers value consumption substantially more than sellers there is some randomness and informational constraints make asset trading useful we show that there is an incentive compatible expansionary policy that dominates all incentive compatible contractionary policies