Toward a Modern Macroeconomic Model Usable for Policy Analysis

This paper presents a macroeconomic model that is both a completely specified dynamic general equilibrium model and a probabilistic model for time series data. We view the model as a potential competitor to existing ISLM-based models that continue to be used for actual policy analysis. Our approach is also an alternative to recent efforts to calibrate real business cycle models. In contrast to these existing models, the one we present embodies all the following important characteristics: i) It generates a complete multivariate stochastic process model for the data it aims to explain, and the full specification is used in the maximum likelihood estimation of the model; ii) It integrates modeling of nominal variables -- money stock, price level, wage level, and nominal interest rate -- with modeling real variables; iii) It contains a Keynesian investment function, breaking the tight relationship of the return on investment with the capital-output ratio; iv) It treats both monetary and fiscal policy explicitly; v) It is based on dynamic optimizing behavior of the private agents in the model. Flexible-price and sticky-price versions of the model are estimated and their fits are evaluated relative to a naive model of no-change in the variables and to an unrestricted VAR. The paper displays the model's implications for the dynamic responses to structural shocks, including policy shocks, and evaluates the relative importance of various shocks for determining economic fluctuations.

Psychological impact of identifying character strengths in people with psychosis

A one group pre-post test design investigated the impact of identifying character strengths using the Values In Action Inventory of Strengths (VIA-IS) with individuals with early psychosis (N = 29). Post-test improvements in positive affect and cognitive performance were observed. Neither self-esteem nor self-efficacy improved. The technique appears feasible for use within early intervention services. Adverse consequences should be monitored and additional components considered to enhance benefits

What Does Monetary Policy Do?

macroeconomics, monetary policy

Femtosecond probing of bimolecular reactions: The collision complex

Progress has been made in probing the femtosecond dynamics of transition states of chemical reactions.(1) The "half-collision" case of unimolecular reactions has been experimentally investigated for a number of systems and much theoretical work has already been developed.(2) For bimolecular reactions, the case of full collision, the zero of time is a problem which makes the femtosecond temporal resolution of the dynamics a difficult task

The K-theory of twisted multipullback quantum odd spheres and complex projective spaces

We find multipullback quantum odd-dimensional spheres equipped with natural $U(1)$-actions that yield the multipullback quantum complex projective spaces constructed from Toeplitz cubes as noncommutative quotients. We prove that the noncommutative line bundles associated to multipullback quantum odd spheres are pairwise stably non-isomorphic, and that the $K$-groups of multipullback quantum complex projective spaces and odd spheres coincide with their classical counterparts. We show that these $K$-groups remain the same for more general twisted versions of our quantum odd spheres and complex projective spaces.Comment: The proof of Theorem 0.1(3) corrected, 35 pages. To appear in Journal of Noncommutative Geometr

Femtosecond real-time probing of reactions. VIII. The bimolecular reaction Br+I2

In this paper, we discuss the experimental technique for real-time measurement of the lifetimes of the collision complex of bimolecular reactions. An application to the atom–molecule Br+I_2 reaction at two collision energies is made. Building on our earlier Communication [J. Chem. Phys. 95, 7763 (1991)], we report on the observed transients and lifetimes for the collision complex, the nature of the transition state, and the dynamics near threshold. Classical trajectory calculations provide a framework for deriving the global nature of the reactive potential energy surface, and for discussing the real-time, scattering, and asymptotic (product-state distribution) aspects of the dynamics. These experimental and theoretical results are compared with the extensive array of kinetic, crossed beam, and theoretical studies found in the literature for halogen radical–halogen molecule exchange reactions

Co-universal algebras associated to product systems, and gauge-invariant uniqueness theorems

Let X be a product system over a quasi-lattice ordered group. Under mild hypotheses, we associate to X a C*-algebra which is co-universal for injective Nica covariant Toeplitz representations of X which preserve the gauge coaction. Under appropriate amenability criteria, this co-universal C*-algebra coincides with the Cuntz-Nica-Pimsner algebra introduced by Sims and Yeend. We prove two key uniqueness theorems, and indicate how to use our theorems to realise a number of reduced crossed products as instances of our co-universal algebras. In each case, it is an easy corollary that the Cuntz-Nica-Pimsner algebra is isomorphic to the corresponding full crossed product.Comment: 40 pages, 2 figures; v2: minor changes to the introduction, references added and update

Constructing an advanced software tool for planetary atmospheric modeling

Scientific model building can be an intensive and painstaking process, often involving the development of large and complex computer programs. Despite the effort involved, scientific models cannot be easily distributed and shared with other scientists. In general, implemented scientific models are complex, idiosyncratic, and difficult for anyone but the original scientist/programmer to understand. We believe that advanced software techniques can facilitate both the model building and model sharing process. In this paper, we describe a prototype for a scientific modeling software tool that serves as an aid to the scientist in developing and using models. This tool includes an interactive intelligent graphical interface, a high level domain specific modeling language, a library of physics equations and experimental datasets, and a suite of data display facilities. Our prototype has been developed in the domain of planetary atmospheric modeling, and is being used to construct models of Titan's atmosphere