dynamic banking a reconsideration financially intermediated and stock market consumption investment allocations with and without governmental interventions are compared in a welfare sense in overlapping generation economies with and without shocks to agents intertemporal preferences we first show that in economies with preference shocks governmental interventions subject to the same information requirements as those imposed on financial intermediaries lead to stock market allocations that are not inferior to those attained under financial intermediation second we argue that the necessary interventions are qualitatively no different from those required to implement stationary optimal allocations in olg models without shocks to agents intertemporal consumption preferences

dynamic efficiency in overlapping generations models with stochastic production abstract we consider an overlapping generations economy as in diamond amer econ rev 55 1965 1126 1150 with stochastic production we define two types of efficiency for feasible production consumption allocations using first and second degree stochastic dominance we obtain a complete characterization of inefficiency of type i in this model for each given sequence of strictly concave utility functions for all generations the existence of a competitive equilibrium is proved it is shown that each competitive allocation is short run efficient of type ii

characterizing efficiency in stochastic overlapping generations models abstract we introduce uncertainty about production in diamond s olg model we compare any two feasible consumption production allocations using stochastic ordering and define two types of efficient allocations given initial capital stock for stationary allocations it is shown that a necessary and sufficient condition for efficiency type i is that e log r is greater or equal to log 1 n where r generates the stationary interest factors corresponding to this allocation n is the population growth rate a complete characterization of type ii efficient allocations is derived using the property of cyclical monotonicity between each generation s consumption allocation and the relevant interest rates

optimism pessimism and financial bubbles this paper shows that it is possible to extend the scope of the existence of rational bubbles when uncertainty is introduced associated with rank dependent expected utility this rdu assumption can be viewed as a transformation of probabilities depending on the pessimism optimism of the agent the results show that pessimism favors the existence of deterministic bubbles when optimism may promote the existence of stochastic bubbles moreover under pessimism the rdu assumption may generate multiple bubbly equilibria the rdu assumption also leads to new conditions ensuring the absence of pareto optimality of the competitive equilibrium without bubbles these conditions still govern the existence of bubbles

debt deficits and finite horizons the stochastic case abstract we introduce aggregate uncertainty and complete markets into blanchard s 1985 perpetual youth model we derive a simple expression for the pricing kernel that can be used to close a variety of equilibrium models in which the set of agents changes over time

stochastic olg models market structure and optimality for a general class of pure exchange olg economies under uncertainty we provide a complete characterization of the efficency properties of competitive equilibria when markets are only sequentially complete and the criterion of efficency is conditional pareto optimality we also consider a particular case in which markets fail to be even sequentially complete and provide a characterization when the criterion of efficency is weakened to ex post pareto optimality

pricing and hedging interest rate options evidence from cap floor markets we examine the pricing and hedging performance of interest rate option pricing models using dailydata on us dollar cap and floor prices across both strike rates and maturities our results show that fitting the skew of the underlying interest rate probability distribution provides accurate pricing results within a one factor framework however for hedging performance introducing a second stochastic factor is more important than fitting the skew of the underlying distribution this constitutes evidence against claims in the literature that correctly specified and calibrated one factor models could replace multi factor models for consistent pricing and hedging of interest rate contingent claims 2004 elsevier b v all rights reserved

asset prices debt constraints and inefficiency abstract we consider possibly non stationary economies with endogenous solvency constraints under uncertainty over an infinite horizon as in alvarez and jermann 2000 5 a sort of cass criterion cass 1972 10 completely characterizes constrained inefficiency under the hypothesis of uniform gains from risk sharing which is always satisfied in stationary economies when the autarchy is constrained inefficient uniform gains from risk sharing also guarantee a finite value of the intertemporal aggregate endowment at a constrained optimum hence no equilibrium exhibits a null interest rate in the long run finally constrained inefficiency occurs if and only if there exists a feasible redistribution producing a welfare improvement at all contingencies

a one factor model of interest rates and its application to treasury bond options 1990 a one factor model of interest rates and its application to treasury bond options financial analysts journal vol 46 no 1 pp 33 39

term structure movements and pricing interest rate contingent claims this paper derives an arbitrage free interest rate movements model ar model this model takes the complete term structure as given and derives the subsequent stochastic movement of the term structure such that the movement is arbitrage free we then show that the ar model can be used to price interest rate contingent claims relative to the observed complete term structure of interest rates this paper also studies the behavior and the economics of the model our approach can be used to price a broad range of interest rate contingent claims including bond options and callable bonds

dominant root characterization of pareto optimality and the existence of optimal equilibria in stochastic overlapping generations models abstract we characterize pareto optimality of interior stationary allocations in single good overlapping generations models with stochastic aggregate shocks and heterogeneous but recurring generations an interior stationary allocation is pareto optimal if and only if it is an equilibrium allocation and the associated contingent claims price matrix has a dominant root less than or equal to unity we then use this characterization to show that there always exists an optimal equilibrium with or without valued fiat money

one factor interest rate models and the valuation of interest rate derivative securities this paper compares different approaches to developing arbitrage free models of the term structure it presents a numerical procedure that can be used to construct a wide range of one factor models of the short rate that are both markov and consistent with the initial term structure of interest rates

bond and option pricing when short rates are lognormal this article describes a one factor model for bond and option pricing that is based on the short term interest rate and that allows the target rate mean reversion and local volatility to vary deterministically through time for any horizon the distribution of possible short rates is lognormal so the rate neither falls below zero nor reflects off a barrier at zero a model like this allows one to match the yield curve the volatility curve and the cap curve surprisingly adding to future local volatility lowers the volatility curve a conventional binary tree with probabilities of 0 5 but variable time spacing is used to value bonds and options when the inputs are constant the slope of the yield curve starts out positive and ends up negative while its curvature shifts from negative to positive even when mean reversion is zero the volatility curve has a negative slope the differential cap curve rises steeply through the effects of volatility and then falls steeply through the effects of discounting and a falling forward rate used as the strike price

life cycle economies and aggregate fluctuations do the implications for business cycle issues change when we switch from studying infinitely lived representative agent models to more sophisticated demographic structures with finitely lived agents this article addresses that question by using a large overlapping generations model that is calibrated to u s demographic properties microeconomic evidence and national income and product accounts the finding is that the answers obtained are basically the same for the two kinds of models the article also explores the relative volatility of hours across age groups an issue that cannot be addressed by using the infinitely lived representative agent abstraction

informational diversity over time and the optimality of monetary equilibria abstract the temporal realizations of a random state variable in an overlapping generations model create an informational diversity between members of different generations and require a reexamination of the optimality that competitive equilibria might display in such an environment using an optimality criterion that reflects this informational diversity we prove the optimality of competitive equilibrium in a model with a fixed stock of fiat money a single spot market and good endowments that follow a markov process the need for an optimality criterion that incorporates informational diversity is further motivated by studying the same model with the operation of complete contingent commodities markets

implausible results or implausible data anomalies in the construction of value added data and implications for estimates of price cost markups in a recent article in this journal robert hall 1988 argued that many american industries charge prices well above marginal costs suggesting either that firms fail to maximize profits or that the possession of substantial market power by firms is the rule rather than the exception hall found price exceeding marginal cost not only in manufacturing where high concentration and the plausible existence of important economies of scale suggest the importance of market power but in relatively unconcentrated nonmanufacturing industries as well subsequent research has confirmed hall s claim that price exceeds marginal cost in u s manufacturing industries domowitz hubbard and petersen 1988 applied hall s method to a more detailed and complete manufacturing data set and rejected the null of price equal to marginal cost at high levels of significance hall however analyzes nonmanufacturing industries as well since theories of the causes of markups can be tested more easily with a larger sample of industries and since further work to uncover the determinants and welfare effects of the market power apparently possessed by u s firms would

implied volatility functions in arbitrage free term structure models abstract we test six term structure models in the heath jarrow and morton 1992 class using eurodollar futures and options data from 1987 1992 we study the time series of implied interest rate volatilities from these models using one day lagged implied volatilities our one and two parameter models simultaneously price an average of 18 5 options each day with an average absolute error of one and a half to two basis points although the models fit well we document systematic strike price and time to maturity biases for all models we also implement simple trading strategies to test whether the models identify genuine biases

existence and optimality of currency equilibrium in stochastic overlapping generations models the pure endowment case abstract we consider a pure exchange stochastic overlapping generations economy sufficient conditions for the existence of a monetary equilibrium and a characterization of optimality are provided it is shown that in a monetary equilibrium currency provides partial insurance and that the equilibrium allocation is optimal it is also shown that if an allocation is optimal the contingent claim prices associated with it are such that in an average sense the present value of the social endowment is bounded

safe debt risky capital the author extends the diamond 1965 model of national debt in two directions she first introduces technological uncertainty and then she allows the stock of debt to vary the author studies the dynamical equilibria of the resulting stochastic system and she establishes conditions for the existence of stationary states that are expressed in terms of invariant distributions since conditions that ensure the existence of a stochastic stationary state with positive debt are very restrictive in this model financial instability is a pervasive phenomenon and allocations are in general dynamically inefficient copyright 1994 by the london school of economics and political science

pricing interest rate derivative securities this article shows that the one state variableinterest rate models of vasicek 1977 and cox ingersoll and ross 1985b can be extended sothat they are consistent with both the current termstructure of interest rates and either the currentvolatilities of all spot interest rates or the currentvolatilities of all forward interest rates theextended vasicek model is shown to be very tracta ble analytically the article compares option pricesobtained using the extended vasicek model withthose obtained using a number of other models