The Dynamic Striated Metropolis-Hastings Sampler for High-Dimensional Models
Having efficient and accurate samplers for simulating the posterior distribution is crucial for Bayesian analysis. We develop a generic posterior simulator called the "dynamic striated Metropolis-Hastings (DSMH)" sampler. Grounded in the Metropolis-Hastings algorithm, it draws its strengths from both the equi-energy sampler and the sequential Monte Carlo sampler by avoiding the weaknesses of the straight Metropolis-Hastings algorithm as well as those of importance sampling. In particular, the DSMH sampler possesses the capacity to cope with incredibly irregular distributions that are full ...
Risk Management for Sovereign Debt Financing with Sustainability Conditions
We develop a model of debt sustainability analysis with optimal financing decisions in the presence of macroeconomic, financial and fiscal uncertainty. We define a coherent measure of refinancing risk, and trade off the risks of debt stock and flow dynamics, subject to debt sustainability constraints and endogenous risk and term premia. We optimize both static and dynamic financing strategies, compare them with several simple rules and consol financing to demonstrate economically significant effects of optimal financing, and show that the stock-flow tradeoff can be critical for ...
Tractable latent state filtering for non-linear DSGE models using a second-order approximation
This paper develops a novel approach for estimating latent state variables of Dynamic Stochastic General Equilibrium (DSGE) models that are solved using a second-order accurate approximation. I apply the Kalman filter to a state-space representation of the second-order solution based on the ?pruning? scheme of Kim, Kim, Schaumburg and Sims (2008). By contrast to particle filters, no stochastic simulations are needed for the filter here--the present method is thus much faster. In Monte Carlo experiments, the filter here generates more accurate estimates of latent state variables than the ...
Replicating and Projecting the Path of COVID-19 with a Model-Implied Reproduction Number
We fit a simple epidemiology model to daily data on the number of currently-infected cases of COVID-19 in China, Italy, the United States, and Brazil. These four countries can be viewed as representing different stages, from late to early, of a COVID-19 epidemic cycle. We solve for a model-implied effective reproduction number Rt each day so that the model closely replicates the daily number of currently infected cases in each country. Using the model-implied time series of Rt, we construct a smoothed version of the in-sample trajectory which is used to project the future evolution of Rt and ...
A Generalized Approach to Indeterminacy in Linear Rational Expectations Models
We propose a novel approach to deal with the problem of indeterminacy in Linear Rational Expectations models. The method consists of augmenting the original state space with a set of auxiliary exogenous equations to provide the adequate number of explosive roots in presence of indeterminacy. The solution in this expanded state space, if it exists, is always determinate, and is identical to the indeterminate solution of the original model. The proposed approach accommodates determinacy and any degree of indeterminacy, and it can be implemented even when the boundaries of the determinacy region ...
Likelihood Evaluation of Models with Occasionally Binding Constraints
Applied researchers interested in estimating key parameters of DSGE models face an array of choices regarding numerical solution and estimation methods. We focus on the likelihood evaluation of models with occasionally binding constraints. We document how solution approximation errors and likelihood misspecification, related to the treatment of measurement errors, can interact and compound each other.
Some Implications of Uncertainty and Misperception for Monetary Policy
When choosing a strategy for monetary policy, policymakers must grapple with mismeasurement of labor market slack, and of the responsiveness of price inflation to that slack. Using stochastic simulations of a small-scale version of the Federal Reserve Board?s principal New Keynesian macroeconomic model, we evaluate representative rule-based policy strategies, paying particular attention to how those strategies interact with initial conditions in the U.S. as they are seen today and with the current outlook. To do this, we construct a current relevant baseline forecast, one that is loosely ...
Asymmetric Information and the Death of ABS CDOs
A key feature of the 2007 financial crisis is that for many securities trading had ceased; where trading did occur, market prices were well below intrinsic values, especially for ABS CDOs. One explanation is that information had been asymmetric, with sellers having better information than buyers. We first show the information advantages sellers had over buyers in both the issuance of CDOs and, through vertical integration, performance of the CDO collateral that could well have disrupted trading after the onset of the crisis. Using a ?workhorse" model for pricing securities under asymmetric ...
The market resources method for solving dynamic optimization problems
We introduce the market resources method (MRM) for solving dynamic optimization problems. MRM extends Carroll?s (2006) endogenous grid point method (EGM) for problems with more than one control variable using policy function iteration. The MRM algorithm is simple to implement and provides advantages in terms of speed and accuracy over Howard?s policy improvement algorithm. Codes are available.
Optimal monetary policy regime switches
Given regime switches in the economy?s growth rate, optimal monetary policy rules may respond by switching policy parameters. These optimized parameters differ across regimes and from the optimal choice under fixed regimes, particularly in the inflation target and interest rate inertia. Optimal switching rules produce welfare gains relative to constant rules, with switches in the implicit real interest rate used for policy and the degree of interest rate inertia producing the largest gains. However, gains from switching rules decrease if the monetary authority trades-off the probability of ...