using real option analysis for highly uncertain technology investments the case of wind energy technology this study examines the feasibility of using a theoretical model and empirical analysis methods to value renewable energy re investment from perspective of real option analysis roa based on use of a roa approach the re value is evaluated with respect to its ability to conform to the main sensitivity analysis of re investment as well as an empirical method devised to value re investment by using actual data the economic intuitiveness underlying the decision making process for re investment is elucidated while empirical analysis is performed to demonstrate the effectiveness of the options value embedded in current development planning in taiwan for wind energy in addition to revealing the advantages of re development when considering real option analytical results indicate that roa is a highly effective means of quantifying how investment planning uncertainty including managerial flexibility influences re development besides evaluating the value of current re investment this study demonstrates that results of the theoretical model empirical analysis and sensitivity analysis correlate well with each other restated the value of developing re increases when increasing the underlying price time to maturity risk free rate and volatility conversely the value of developing re decreases when increasing the exercise price

inefficient credit booms this paper studies the welfare properties of competitive equilibria in an economy with financial frictions hit by aggregate shocks in particular it shows that competitive financial contracts can result in excessive borrowing ex ante and excessive volatility ex post even though from a first best perspective the equilibrium always displays under borrowing from a second best point of view excessive borrowing can arise the inefficiency is due to the combination of limited commitment in financial contracts and the fact that asset prices are determined in a spot market this generates a pecuniary externality that is not internalized in private contracts the model provides a framework to evaluate preventive policies which can be used during a credit boom to reduce the expected costs of a financial crisis copyright 2008 wiley blackwell

prices and investment with collateral and default abstract this paper uses the framework of an olg economy with three period lived agents in which a durable good serves as collateral for loans to study the effect of an unanticipated income shock when the economy is in a steady state equilibrium we focus on the consequence of default on loans when the value of the collateral falls below the value of the debt it secures we analyze the impulse response functions of the price and production of the durable good and show that there is an asymmetry between the response of the price and investment of the durable good to a positive and a negative income shock arising from default on the collateralized loans we show that this asymmetry can be seen in the data on housing prices and construction and is attributable to the default on mortgages in periods of decreasing prices which acts as a turbo mechanism magnifying the decline in investment

solution of macromodels with hansen sargent robust policies some extensions abstract we summarize some methods useful in formulating and solving hansen sargent robust control problems and suggest extensions to discretion and simple rules matlab octave and gauss software is provided we illustrate these extensions with applications to the term structure of interest rates the time inconsistency of optimal monetary policy the effects of expectations on the variances of inflation and output and on whether central banks should make their forecasts public

securitized markets international capital flows and global welfare we study the effect of collateralized lending and securitization on the global supply of securitized assets welfare and international net and gross capital flows in a two country general equilibrium model with idiosyncratic investment risk the financial sectors in the two countries home and foreign differ by the collateral requirement for investment loans with home requiring lower margins in autarky home endogenously supplies more assets and enables more risk sharing upon financial integration capital flows from foreign to home leading to lower interest rates and an increase in the global supply of assets foreign enjoys substantial welfare gains through better risk sharing and portfolio reallocation while the welfare experience for home is ambiguous gross capital flows arise when agents face aggregate shocks to the expected payoff to investment projects but can collapse when shocks concern the variance of returns

verifying competitive equilibria in dynamic economies in this paper i examine e equilibria of stationary dynamic economies with heterogeneous agents and possibly incomplete financial markets i give a simple example to show that even for arbitrarily small e 0 allocation and prices can be far away from exact equilibrium allocations and prices that is errors in market clearing or individuals optimality conditions do not provide enough information to assess the quality of an approximation i derive a sufficient condition for an e equilibrium to be close to an exact equilibrium if the economic fundamentals are semi algebraic one can verify computationally whether this condition holds the condition can be interpreted economically as a robustness requirement on the set of e equilibria which form a neighbourhood of the computed approximation i illustrate the main result and the computational method using an infinite horizon economy with overlapping generations and incomplete financial markets copyright 2011 oxford university press

on non existence of markov equilibria in competitive market economies abstract this paper presents some examples of regular dynamic economies with externalities and taxes that either lack existence of a markov equilibrium or such equilibrium is not continuous these examples pose further challenges for the analysis and computation of these economies journal of economic literature classification numbers c10 c62

robust control with commitment a modification to hansen sargent i examine the hansen and sargent 2003 robust control of forward looking models journal of monetary economics 50 581 604 formulation of the robust stackelberg problem and show that their method of constructing the approximating equilibrium is generally invalid i then turn to the hansen and sargent 2007 robustness manuscript version dated march 22 2007 treatment which responding to the problems raised in this paper changes subtly but importantly how the robust stackelberg problem is formulated in the context of hansen and sargent 2007 robustness manuscript version dated march 22 2007 i prove first that their method for obtaining the approximating equilibrium is now equivalent to the one developed in this paper and second that the worst case specification errors are not subject to a time consistency problem in the context of the erceg et al 2000 optimal monetary policy with staggered wage and price contracts journal of monetary economics 46 281 313 sticky wage sticky price model i find that a robust central bank will fear primarily that the supply side of its approximating model is misspecified and that robustness affects importantly central bank promises about future policy

learning from private and public observations of othersʼ actions we study how a continuum of agents learn about disseminated information by observing others actions every period each agent observes a public and private noisy signal centered around the aggregate action taken by the population the public signal represents an endogenous aggregate variable such as a price or a quantity the private signal represents the information gathered through private communication and local interactions we identify conditions such that the average learning curve is s shaped learning is slow initially intensifies rapidly and finally converges slowly to the truth we show that increasing public information always slows down learning in the long run and under some conditions reduces welfare lastly optimal diffusion of information requires that agents strive to be different agents need to be rewarded for choosing actions away from the population average

testing for indeterminacy an application to u s monetary policy reply this paper considers a prototypical new keynesian model in which the equilibrium is undetermined if monetary policy is passive the likelihood based estimation of dynamic equilibrium models is extended to allow for indeterminacies and sunspot fluctuations we construct posterior weights for the determinacy and indeterminacy region of the parameter space and estimates for the propagation of fundamental and sunspot shocks according to the estimated model u s monetary policy post 1982 is consistent with determinacy whereas the pre volcker policy is not we find that before 1979 indeterminacy substantially altered the propagation of shocks

informal insurance arrangements with limited commitment theory and evidence from village economies recent work on consumption allocations in village economies finds that idiosyncratic variation in consumption is systematically related to idiosyncratic variation in income thus rejecting the hypothesis of full risk pooling we attempt to explain these observations by adding limited commitment as an impediment to risk pooling we provide a general dynamic model and completely characterise efficient informal insurance arrangements constrained by limited commitment and test the model using data from three indian villages we find that the model can fully explain the dynamic response of consumption to income but that it fails to explain the distribution of consumption across households

robust monetary policy with the cost channel recent research argues that model uncertainty leads the central bank to adjust interest rates stronger to exogenous disturbances than under certainty this paper investigates whether the introduction of a cost channel of monetary transmission whose presence is empirically supported changes the impact of model uncertainty on interest rate setting the model is simple enough to facilitate an analytical solution i find that the presence of the cost channel dampens the effect of model uncertainty on interest rate setting and can offset the activist policy stance a richer model that allows for persistent supply and demand shocks corroborates these findings

u s inequality debt constraints or incomplete asset markets abstract to examine the role of debt constraints and incomplete asset markets lack of insurance markets in explaining u s inequality we run horse races between competing models for a widely used model we decompose inequality into its fundamental driving forces the underlying source of inequality in all models is uninsurable idiosyncratic risk both debt constraints and incomplete asset markets are needed to account for inequality but asset market incompleteness is the key friction it better accounts for the concentration and dispersion of wealth and is the most costly friction in terms of welfare tight debt constraints are important for explaining the lower tail of the wealth distribution

considering the investment decisions with real options games approach abstract the mix of games theory with the real options has been a dynamic range of exploration in the most recent decade the engaging quality of the specialists for displaying aggressive speculation choices by blending ideas from both hypotheses is on account of a venture choice in a focused business sector can be seen in its substance as a game between firms in this paper we expand a model to consider finite horizon real option games under incomplete information with various parameters in incomplete information games firms actions express significant information about profitability to contestants the encapsulation of this information proposed original blocks in models with strategic interactions this is because of circularity where best exercise decisions are based on previous decisions taken which at a given time are quiet to be mentioned because about the dynamic programming principle we expand an extended version of the least squares monte carlo algorithm to confront these results the model can aid in understanding the relation between strategic optionality and information besides how this influences the best decision policy and its value results we find the informational feature is of great significance for firms best decision policy and optimization of project values

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

information revelation through option exercise in many real world situations agents must formulate option exercise strategies with imperfect information in such a setting agents may infer the private signals of other agents through their observed exercise strategies the building of an office building the drilling of an exploratory oil well and the commitment of a pharmaceutical company toward the research of a new drug all convey private information to other market participants this article develops an equilibrium framework for option exercise games with asymmetric private information many interesting aspects of the patterns of equilibrium exercise are analyzed in particular informational cascades where agents ignore their private information and jump on the exercise bandwagon may arise endogenously article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

a dynamic duopoly investment game without commitment under uncertain market expansion abstract we model capacity building investments in a homogeneous product duopoly facing uncertain demand growth capacity building is achieved through the addition of production units that are durable and lumpy and whose cost is irreversible while building their capacity over time firms compete a la cournot in the product market given their installed capacity there is no exogenous order of moves no commitment regarding future decisions and no finite horizon we investigate markov perfect equilibrium mpe paths of the investment game which may include episodes during which firms invest at different times a preemption pattern and episodes in which firms invest simultaneously a tacit collusion pattern these episodes may alternate and are typically several when firms have yet to invest in capacity the sole pattern that is mpe compatible is a preemption episode firms invest at different times but have equal value the first such investment may occur earlier and therefore be riskier than socially optimal when both firms hold capacity tacit collusion episodes may be mpe compatible firms invest simultaneously at a postponed time hence holding back production in the meantime thereby generating an investment wave in the industry such investment episodes are more likely with higher demand volatility faster market growth and lower cost of capital discount rate

optimal security design how should new securities be designed traditional theories have little to say on this the literature on capital structure and general equilibrium theories with incomplete markets take the securities firms issue as exogenous this paper explicitly incorporates the transaction costs of issuing securities and develops a model where the instruments that are traded are chosen optimally and the economy s market structure is endogenous among other things it is shown that the firm s income stream should be split so that in every state all payoffs are allocated to the security held by the group that values them most this abstract was borrowed from another version of this item

the effect of uncertainty on investment evidence from texas oil drilling this paper estimates the response of investment to changes in uncertainty using data on oil drilling in texas and the expected volatility of the future price of oil using a dynamic model of firms investment problem i find that i the response of drilling activity to changes in price volatility has a magnitude consistent with the optimal response prescribed by theory ii the cost of failing to respond to volatility shocks is economically significant and iii implied volatility data derived from futures options prices yields a better fit to firms investment behavior than backward looking volatility measures such as garch jel c58 d92 g13 g31 l71 q31 the real options literature beginning with marschak 1949 and arrow 1968 and developed in bernanke 1983 pindyck 1991 and dixit and pindyck 1994 explains how firms should make decisions about investments that involve sunk costs real options theory views such investments as options in that at any point in time a firm may choose to either invest immediately or delay and observe the evolution of the investment s payoff a key insight is that the option to delay has value when future states of the world with positive returns to investing and states with negative returns are both possible even holding the expected future return constant at its present level thus in the presence of irreversibility and uncertainty a naive investment timing rule proceed with an investment if its expected benefit even slightly exceeds its cost is suboptimal because it does not account for the value of continuing to hold the option instead firms should delay irreversible investments until a significant gap develops between the investments expected benefits and costs moreover as uncertainty increases real options theory tells us that the incentive to delay should grow stronger and the gap between the expected benefit and cost necessary to trigger investment should widen while real options theory therefore prescribes how firms should carry out irreversible investments in uncertain environments it is not empirically well known

inflation dynamics and the cost channel of monetary transmission evidence from vector autoregressions indicates that the impact of interest rate shocks on macroeconomic aggregates can substantially be affected by the so called cost channel of monetary transmission in this paper we apply a structural approach to examine the relevance of the cost channel for inflation dynamics in g7 countries we augment the so called hybrid new keynesian philips curve by letting firms costs for external funds rise with the short run nominal interest rate our estimates reveal that the magnitude of this cost channel strongly varies between countries including member countries of the emu in accordance with differences in their financial systems simulations of a new keynesian model further show that the presence of the cost channel substantially affects the transmission of monetary policy shocks in particular the inflation response

a bayesian approach to real options the case of distinguishing between temporary and permanent shocks traditional real options models demonstrate the importance of the option to wait due to uncertainty over future shocks to project cash flows however there is often another important source of uncertainty uncertainty over the permanence of past shocks adding bayesian uncertainty over the permanence of past shocks augments the traditional option to wait with an additional option to learn the implied investment behavior differs significantly from that in standard models for example investment may occur at a time of stable or decreasing cash flows respond sluggishly to cash flow shocks and depend on the timing of project cash flows during the past two decades the real options approach to valuation of irreversible investment opportunities has become part of the mainstream literature in financial economics the central idea is that the opportunity to invest is equivalent to an american call option on the underlying investment project as a consequence the problem of optimal investment timing is analogous to the optimal exercise decision for an american option applications of the real options approach are now numerous 1 one feature that is common to virtually all real options models is that the underlying uncertainty pertains only to future shocks since future cash flows are uncertain there is an important opportunity cost of investing today the value of the asset might go up so that tomorrow will be an even better time to invest this opportunity cost is often referred to in the literature as the option

dynamic competitive economies with complete markets and collateral constraints in this article we examine the competitive equilibria of a dynamic stochastic economy with complete markets and collateral constraints we show that provided the sets of asset pay offs and of collateral levels are sufficiently rich the equilibrium allocations with sequential trades and collateral constraints are equivalent to those obtained in arrow debreu markets subject to a series of limited pledgeability constraints we provide both necessary and sufficient conditions for equilibria to be pareto efficient and show that when collateral is scarce equilibria are not only pareto inefficient but also often constrained inefficient in the sense that imposing tighter borrowing restrictions can make everybody in the economy better off we derive sufficient conditions for the existence of markov equilibria and for the case of two agents for the existence of equilibria that have finite support these equilibria can be computed with arbitrary accuracy and the model is very tractable

the dynamics of financially constrained arbitrage we develop a model of financially constrained arbitrage and use it to study the dynamics of arbitrage capital liquidity and asset prices arbitrageurs exploit price discrepancies between assets traded in segmented markets and in doing so provide liquidity to investors a collateral constraint limits their positions as a function of capital we show that the dynamics of arbitrage activity are self correcting following a shock that depletes arbitrage capital profitability increases and this allows capital to be gradually replenished spreads increase more and recover faster for more volatile trades although arbitrageurs cut their positions in these trades the least when arbitrage capital is more mobile across markets liquidity in each market generally becomes less volatile but the reverse may hold for aggregate liquidity because of mobility induced contagion

distinguished lecture on economics in government what central bankers could learn from academics and vice versa academic writing about monetary policy has been useful to practical central bankers but more of certain aspects of the economists way of thinking could profitably be imported on the other hand academics could improve their analysis and make it more useful to policymakers if they would pay more attention to certain real world aspects of monetary policy the author draws on his experience at the federal reserve board to point out a number of specific lessons for each side

the effect of liquidity constraints on consumption a cross sectional analysis this paper examines the effect of liquidity constraints on consumption expenditures using a single year cross section data set a reduced form equation for consumption is estimated on high saving households by the tobit procedure to account for the selectivity bias since high saving households are not likely to be liquidity constrained the estimated equation is an appropriate description of how desired consumption that would be forthcoming without liquidity constraints is related to the variables available in the cross section data when the reduced form equation is used to predict desired consumption the gap between desired consumption and measured consumption is most evident for young households

robust monetary policy with the consumption wealth channel abstract this paper studies how the central bank s concerns about model uncertainty affect the design of monetary policy in the presence of wealth effects if all exogenous disturbances are white noises increasing the preference for robustness or the size of wealth effects implies more aggressive policy responses to cost shocks under persistent shocks numerical simulations show that increasing the preference for robustness continues to imply more aggressive responses to cost shocks by contrast stronger wealth effects lead to less aggressive responses dampening the effect of model uncertainty on interest rate dynamics

international coordination of fiscal policy in limiting economies we examine the limiting behavior of cooperative and noncooperative fiscal policies as countries market power goes to zero we show that these policies converge if countries raise revenues through lump sum taxation however if there are unremovable domestic distortions such as distorting taxes there can be gains to coordination even when a single country s policy cannot affect world prices these results differ from the received wisdom in the optimal tariff literature the key distinction is that contrary to the tariff literature the spending decisions of governments are explicitly modeled

strategic entry in a triopoly market of firms with asymmetric cost structures abstract this paper examines the strategic investment timing decision in a triopoly market comprising firms with asymmetric cost structures we present three novel results first in the case where there are relatively small cost asymmetries between firms and a relatively small first mover advantage the firm with the lowest cost structure is not always the first investor in other cases the firm with the lowest cost structure is the first investor second an increase in volatility increases the possibility that a firm without the lowest cost structure is the first investor finally even in the three asymmetric firm model we show that the first investor threshold is larger in a triopoly than in a duopoly although it is smaller in a duopoly than in a monopoly

option exercise games an application to the equilibrium investment strategies of firms under the standard real options approach to investment under uncertainty agents formulate optimal exercise strategies in isolation and ignore competitive interactions however in many real world asset markets exercise strategies cannot be determined separately but must be formed as part of a strategic equilibrium this article provides a tractable approach for deriving equilibrium investment strategies in a continuous time cournot nash framework the impact of competition on exercise strategies is dramatic for example while standard real options models emphasize that a valuable option to wait leads firms to invest only at large positive net present values the impact of competition drastically erodes the value of the option to wait and leads to investment at very near the zero net present value threshold copyright 2002 oxford university press

real options and preemption under incomplete information abstract this paper introduces incomplete information and preemption into an equilibrium model of firms facing real investment decisions the optimal investment strategy may lie anywhere between the zero npv trigger level and the optimal strategy of a monopolist depending on the distribution of competitors costs and the implied fear of preemption our model implies that the equity returns of firms which hold real options and are subject to preemption will contain jumps and positive skewness

rational asset pricing bubbles this paper provides a fairly systematic study of general economic conditions under which rational asset pricing bubbles may arise in an intertemporal competitive equilibrium framework our main results are concerned with nonexistence of asset pricing bubbles in those economies these results imply that the conditions under which bubbles are possible including some well known examples of monetary equilibria are relatively fragile this paper is concerned with the conditions under which asset prices in an intertemporal competitive equilibrium are equal to the present value of the streams of future dividends to which each asset represents a claim according to a central result of the theory of finance this is very generally true in the case of economies with trading at only a finite sequence of dates as long as there are no restrictions upon transactions other than that associated with possible incom pleteness of the set of securities that are traded the result is sometimes called the fundamental theorem of asset pricing here we consider the extent to which such a result continues to be valid in the case of trading over an infinite horizon it has often been observed in the econometric literature on asset pricing bubbles that it is possible in principle for the price of a perpetuity and the dividends on that security to satisfy at all times a present value relation for one period holding returns while the security s price nonetheless does not equal the present value of the stream of dividends expected over the infinite future in such a case the price of the perpetuity is said to involve a bubble component 2 joint stochastic processes for which this component is nonzero are sometimes argued to characterize existing assets for a recent example see froot and obstfeld 1991 but such an inference depends upon aspects of the stochastic

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

optimal monetary policy with the cost channel in the standard new keynesian framework an optimizing policy maker does not face a trade off between stabilizing the inflation rate and stabilizing the gap between actual output and output under flexible prices an ad hoc exogenous cost push shock is typically added to the inflation equation to generate a meaningful policy problem in this paper we show that a cost push shock arises endogenously when a cost channel for monetary policy is introduced into the new keynesian model a cost channel is present when firms marginal cost depends directly on the nominal rate of interest besides providing empirical evidence for a cost channel we explore its implications for optimal monetary policy we show that its presence alters the optimal policy problem in important ways for example both the output gap and inflation are allowed to fluctuate in response to productivity and demand shocks under optimal monetary policy

on efficient distribution with private information this paper is a study of the dynamics of the efficient distribution of consumption in an exchange economy with many consumers each of whom is subject to private idiosyncratic taste shocks we propose a recursive method for finding feasible allocations that are incentivecompatible and that are pareto optimal within this set the method is applied to several parametric examples we find that in an efficient allocation the degree of inequality continually increases with a diminishing fraction of the population receiving an increasing fraction of the resources we discuss the extent to which these allocations can be decentralized via market arrangements this paper is a study of the dynamics of the efficient distribution of consumption in an exchange economy with private information the economy we study has a constant endowment flow of a single non storable consumption good which is to be allocated each period among a large number of consumers each period these consumers experience unpredictable idiosyncratic privately observed taste shocks affecting their marginal utility of current consumption efficiency dictates that more resources be allocated to those consumers who in any given period have a high marginal utility of current consumption

mature or emerging markets competitive duopoly investment decisions abstract we develop a competitive investment model wherein two competing firms consider investing into two projects targeting separately a mature and an emerging market the returns firms obtain from investments into these markets are assumed to follow an s shaped curve and depend on both firms actions considering symmetric environments in terms of investment opportunities we find that different forms of interactions may arise e g prisoner s dilemma and game of chicken and outline corresponding strategies that offer higher returns by exploiting first mover advantages cooperation opportunities and aggressive choices we also discuss the market conditions that can lead to these outcomes finally considering non symmetric environments we show that a firm may be better off when its competitor s budget increases

monetary policy with uncertain parameters this thesis contains four chapters each of which examines different aspects of the uncertainty facing monetary policymakers monetary policy and market interest rates investigates how interest rates set on financial markets respond to policy actions taken by the monetary authorities the reaction of market rates is shown to depend crucially on market participants interpretation of the factors underlying the policy move these theoretical predictions find support in an empirical analysis of the u s financial markets predicting monetary policy using federal funds futures prices examines how prices of federal funds futures contracts can be used to predict policy moves by the federal reserve although the futures prices exhibit systematic variation across trading days and calendar months they are shown to be fairly successful in predicting the federal funds rate target that will prevailafter the next meeting of the federal open market committee from 1994 to 1998 monetary policy with uncertain parameters examines the effects of parameter uncertainty on the optimal monetary policy strategy under certain parameter configurations increasing uncertainty is shown to lead to more aggressive policy in contrast to the accepted wisdom should central banks be more aggressive examines why a certain class of monetary policy models leads to more aggressive policy prescriptions than what is observed in reality these counterfactual results are shown to be due to model restrictions rather than central banks being too cautious in their policy behavior an unrestricted model taking the dynamics of the economy and multiplicative parameter uncertainty into account leads to optimal policy prescriptions which are very close to observed federal reserve behavior

strategic delegation in a legislative bargaining model with pork and public goods abstract this paper examines the incentives of voters to appoint legislators with different preferences from their own the paper adopts an underlying legislative bargaining model proposed by volden and wiseman 2007 in which legislators with heterogeneous preferences divide a fixed budget between a public good and pork projects local public goods we show that voters have an incentive to strategically delegate to affect how the budget is divided at the legislative level when voters preferences for pork are not too strong the incentives for strategic delegation exist to appoint representatives who will direct more money to the public good and not to pork projects this generally results in at least as many representatives as districts that favor the public good the comparative statics predict that when strategic delegation occurs increasing the size of the legislature increases the fraction of the budget spent on the public good

robust optimal policy in a forward looking model with parameter and shock uncertainty this paper characterizes a robust optimal policy rule in a simple forward looking model when the policymaker faces uncertainty about model parameters and shock processes we show that the robust optimal policy rule is likely to involve a stronger response of the interest rate to fluctuations in inflation and the output gap than is the case in the absence of uncertainty thus parameter uncertainty alone does not necessarily justify a small response of monetary policy to perturbations however uncertainty may amplify the degree of super inertia required by optimal monetary policy we finally discuss the sensitivity of the results to alternative assumptions copyright 2007 john wiley sons ltd

asset shortages liquidity and speculative bubbles abstract we study the effect of asset shortages on liquidity in economies with limited enforcement of debt contracts we establish that under a suitable assumption in terms of gains from trade liquidity does not dry up and trading volumes do not disappear as credit conditions worsen the equilibrium outcome becomes arbitrarily close to a purely speculative equilibrium and bubbles occur in the limit the result applies to incomplete markets and more generally to equilibria where collateral constraints interfere with the additivity of the payoff pricing functional

investment under uncertainty does competition matter abstract empirical applications of real options models in competitive environments implicitly exploit the optimality of myopic planning in a seminal paper leahy j v 1993 investment in competitive equilibrium the optimality of myopic behavior quarterly journal of economics 108 1105 1133 shows that the optimal investment strategy of a myopic planner who ignores market entries and exits of competitors as well as the resulting price effects constitutes a market equilibrium under rather general conditions as a result the calculation of optimal investment strategies is simplified considerably because competition does not have to be taken into account in this paper however we demonstrate by using simulation experiments that myopic planning may lead to non optimal investment strategies this is due to the fact that it is difficult or even impossible to specify the correct or equivalent price process for the myopic investor using real world data we quantify the degree of suboptimality and propose measures to reduce the error

growth cycles and market crashes abstract market booms are often followed by dramatic falls to explain this requires an asymmetry in the underlying shocks a straightforward model of technological progress generates asymmetries that are also the source of growth cycles assuming a representative consumer we show that the stock market generally rises punctuated by occasional dramatic falls with high risk aversion bad news causes dramatic increases in prices bad news does not correspond to a contraction of existing production possibilities but to a slowdown in its expansion this economy provides a model of endogenous growth cycles in which recoveries and recessions are dictated by the adoption of innovations journal of economic literature classification numbers o40 g12 o41 o30

strategic investment in technological innovations abstract the aim of this paper is to determine the optimal timing of technology investment of a single firm in a duopoly framework as time passes different technologies are invented which after sometime become available for the firm to adopt the question here is not only when a firm should invest but also which technology should be adopted for different scenarios the optimal technology investment decision is determined outcomes range from pre emption equilibria to equilibria with second mover advantages

stationary equilibria in asset pricing models with incomplete markets and collateral we consider an infinite horizon exchange economy with incomplete markets and collateral constraints as in the two period model of geanakoplos and zame 2002 households can default on their liabilities at any time and financial securities are only traded if the promises associated with these securities are backed by collateral we examine an economy with a single perishable consumption good where the only collateral available consists of productive assets in this model competitive equilibria always exist and we show that under the assumption that all exogenous variables follow a markov chain there also exist stationary equilibria these equilibria can be characterized by a mapping from the exogenous shock and the current distribution of financial wealth to prices and portfolio choices we develop an algorithm to approximate this mapping numerically and discuss ways to implement the algorithm in practice a computational example demonstrates the performance of the algorithm and shows some quantitative features of equilibria in a model with collateral and default

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

delay and information aggregation in stopping games with private information abstract we consider equilibrium timing decisions in a model with a large number of players and informational externalities the players have private information about a common payoff parameter that determines the optimal time to invest they learn from each other in real time by observing past investment decisions we develop new methods of analysis for such large games and we give a full characterization of symmetric equilibria we show that the equilibrium statistical inferences are based on an exponential learning model although the beliefs converge to truth learning takes place too late ex ante welfare is strictly between that without observational learning and that with full information

real options in strategic investment games between two asymmetric firms abstract this paper examines strategic investment games between two firms that compete for optimal entry in a project that generates uncertain revenue flows under asymmetry on both the sunk cost of investment and revenue flows of the two competing firms we investigate the value of real investment options and strategic interaction of investment decisions compared to earlier models that only allow for asymmetry on sunk cost our model demonstrates a richer set of strategic interactions of entry decisions we provide a complete characterization of pre emptive dominant and simultaneous equilibriums by analyzing the relative value of leader s and follower s optimal investment thresholds in a duopoly market with negative externalities a firm may reduce loss of real options value by selecting appropriate pre emptive entry when one firm has a dominant advantage over its competitor both the dominant firm and dominated firm enter at their respective leader s and follower s optimal thresholds when the pre emptive thresholds of both firms happen to coincide the two firms enter simultaneously under positive externalities firms do not compete to lead