Search Results
Working Paper
Finite-Order VAR Representation of Linear Rational Expectations Models: With Some Lessons for Monetary Policy
This paper considers the characterization via finite-order VARs of the solution of a large class of linear rational expectations (LRE) models. I propose a unified approach that uses a companion Sylvester equation to check the existence and uniqueness of a solution to the canonical (first-order) LRE model in finite-order VAR form and a quadratic matrix equation to characterize it decoupling the backward- and forward-looking aspects of the model. I also investigate the fundamentalness of the shocks recovered. Solving LRE models by this procedure is straightforward to implement, general in its ...
Working Paper
Equilibrium with Mutual Organizations in Adverse Selection Economies
An equilibrium concept in the Debreu (1954) theory-of-value tradition is developed for a class of adverse selection economies and applied to the Spence signaling and Rothschild-Stiglitz (1976) adverse selection environments. The equilibrium exists and is optimal. Further, all equilibria have the same individual type utility vector. The economies are large with a finite number of types that maximize expected utility on an underlying commodity space. An implication of the analysis is that the invisible hand works for this class of adverse selection economies.
Working Paper
When does the cost channel pose a challenge to inflation targeting central banks?
In a sticky-price model where firms finance their production inputs, there is both a lower and an upper bound on the central bank's inflation response necessary to rule out the possibility of self-fulfilling inflation expectations. This paper shows that real wage rigidities decrease this upper bound, but coefficients in the range of those on the Taylor rule place the economy well within the determinacy region. However, when there is time-variation in the share of firms who finance their inputs (i.e. Markov-Switching) then inflation targeting interest rate rules are often found to result in ...
Working Paper
Solving asset pricing models with stochastic volatility
This paper provides a closed-form solution for the price-dividend ratio in a standard asset pricing model with stochastic volatility. The solution is useful in allowing comparisons among numerical methods used to approximate the non-trivial closed-form.
Working Paper
Reliably Computing Nonlinear Dynamic Stochastic Model Solutions: An Algorithm with Error Formulas
This paper provides a new technique for representing discrete time nonlinear dynamic stochastic time invariant maps. Using this new series representation, the paper augments the usual solution strategy with an additional set of constraints thereby enhancing algorithm reliability. The paper also provides general formulas for evaluating the accuracy of proposed solutions. The technique can readily accommodate models with occasionally binding constraints and regime switching. The algorithm uses Smolyak polynomial function approximation in a way which makes it possible to exploit a high degree of ...
Working Paper
Global Dynamics in a Search and Matching Model of the Labor Market
We study global and local dynamics of a simple search and matching model of the labor market. We show that the model can be locally indeterminate or have no equilibrium at all, but only for parameterizations that are empirically implausible. In contrast to the local results, we show that the model exhibits chaotic and periodic dynamics for reasonable parameter values both in backward and forward time. In contrast to earlier work, we establish these results analytically without placing numerical restrictions on the parameters.
Report
Constructing Pure-Exchange Economies with Many Equilibria
We develop a restart algorithm based on Scarf’s (1973) algorithm for computing approximate Brouwer fixed points. We use the algorithm to compute all of the equilibria of a general equilibrium pure-exchange model with four consumers, four goods, and 15 equilibria. The mathematical result that motivates the algorithm is a fixed-point index theorem that provides a sufficient condition for uniqueness of equilibrium and a necessary condition for multiplicity of equilibria. Examining the structure of the model with 15 equilibria provides us with a method for constructing higher dimensional models ...
Working Paper
Solving for Optimal Simple Rules in Rational-Expectations Models
This paper presents techniques to solve for optimal simple monetary policy rules in rational expectations models, assuming discretion. The techniques described are notable for the flexibility they provide over the structure of the policy rule being solved for. Specifically, not all state variables need enter the policy rule allowing rules optimal conditional on a given information set to be easily constructed. The algorithms described are compared to related solution methods, and applied to the model in Clarida, Gali, and Gertler (1999).
Journal Article
Closing Small and "Sufficiently" Large Open Economies with Different Asset Structures
There are two important dimensions that matter when we write down a model economy of a country that is open to international financial markets. The first one is its size, and the second one is its asset market structure. Small open economies are price takers so the analysis happens in partial equilibrium, while countries that are “sufficiently" large can affect international prices and the analysis happens in general equilibrium. The second important dimension is the asset market structure. If markets are complete there is full risk sharing, while if markets are incomplete there is not. In ...
Working Paper
Organizational Equilibrium with Capital
This paper proposes a new equilibrium concept - organizational equilibrium - for models with state variables that have a time inconsistency problem. The key elements of this equilibrium concept are: (1) agents are allowed to ignore the history and restart the equilibrium; (2) agents can wait for future agents to start the equilibrium. We apply this equilibrium concept to a quasi-geometric discounting growth model and to a problem of optimal dynamic fiscal policy. We find that the allocation gradually transits from that implied by its Markov perfect equilibrium towards that implied by the ...