The main computational tool for solving SUR or simultaneous equations models is the generalized QR decomposition (GQRD) of an exogenous matrix A and the Cholesky factorization of a dispersion matrix C. Initially the GQRD computes the QRD of A and then the RQD of QC, where Q is an orthogonal...

Sometimes numerical failure of an econometric software package is quite stark: a nonlinear procedure fails to converge; illegal arguments to a function cause an abnormal end; matrices cannot be inverted. Other times a package fails without warning, and these types of failures are particularly...

In this study, we ask whether the presence of precautionary savings substantially reduces the optimal replacement rate in an economy characterized by equilibrium unemployment and moral hazard. In line with previous studies, the optimality criterion based on comparisons of steady states leads to...

This paper considers the cross-sectional aggregation of nonlinear decision rules derived from intertemporal optimization problems under uncertainty, examining in particular (i) the role of aggregation across decision rules of heterogeneous decision makers as a source of variation and persistence...

We evaluate the stability of risk-sharing contracts in the presence of moral hazard. Contracts are rules for sharing output among producers and affect the extent of private investments in production. Organizations, which are identified with the contracts they offer, compete for membership....

Consider a simple world populated with two kinds of individuals, those who work and create wealth (peasants) and those who survive by taking the property of others (bandits). The presence of bandits creates an incentive for peasants to seek protection, to defend their property. But protection is...

In this paper we model Value-at-Risk (VaR) for daily stock index returns using a collection of parametric models of the ARCH family based on the skewed Student distribution. We show that models that rely on a symmetric density distribution for the error term underperform with respect to skewed...

This paper presents techniques to solve for optimal simple monetary policy rules in rational expectations models. Both pre-commitment and discretionary solutions are considered. The techniques described are notable for the flexibility they provide over the structure of the policy rule being...

Incorporating labor market search in general equilibrium models has been shown to generate realistic dynamics in employment, job creation, and job destruction and to increase the magnitude and persistence of the impact of productivity shocks on output. This paper studies the extent to which the...

The paper deals with a newly discovered credit card puzzle. Many US households revolve a balance on high-interest credit cards while holding low-interest liquid or total safe assets that could be used to repay this balance. Such behavior seems to ignore obvious arbitrage opportunities and to...