The Quest for Purchasing Power Parity with a Series-specific Unit Root Test Using Panel Data

A unit root testing procedure is presented that exploits the well-established power advantages of panel estimation while rectifying a deficiency in other panel unit root tests. This procedure, which takes into account contemporaneous cross-correlation and heterogeneous serial correlation of the regression residuals, allows determination of which members of the panel reject the null hypothesis of a unit root and which do not. Applying the procedure to real exchange rates yields results that are in broad agreement with those obtained from single-equation unit root tests. There is little evidence that a unit root can be rejected in dollar-based real exchange rates for the floating rate period.Marketing,

Cavitation and pressure distribution: head forms at zero angle of yaw

https://ir.uiowa.edu/uisie/1032/thumbnail.jp

Monetary policy and stability during six periods in US economic history: 1959–2008: a novel, nonlinear monetary policy rule

We investigate the monetary policy of the Federal Reserve Board during six periods in US economic history 1959–2008. In particular, we examine the Fed’s response to changes in three guiding variables: inflation, π, unemployment, U, and industrial production, y, during periods with low and high economic stability. We identify separate responses for the Fed’s change in interest rate depending upon (i) the current rate, FF, and the guiding variables’ level below or above their average values and (ii) recent movements in inflation and unemployment. The change in rate, FF, can then be calculated. We identify policies that both increased and decreased economic stability

A model-based methodology for the evaluation of computerized group decision making

Increased global competition is forcing organizations to increase their use of group decision making today. Computerized group decision support aids (CGDSAs) are being developed to improve the efficiency of these groups and to improve decision quality. Even though the use of CGDSAs has increased, very little research has been done on the evaluation of CGDSAs. The purpose of this research was to develop a model-based generalized methodology for CGDSA evaluation from the user's perspective. Two models were developed as a foundation for the CGDSA evaluation methodology. The first model was a model of group decision making and the second model was a model of computer-aided group decision making. The group decision making model was based upon a basic input-output model with the problem as the input and the selected alternative as the output. Analogous to how problems are viewed in terms of classical design of experiments, independent variables affect the outcome (problem solution the dependent variable) of the decision making process. As in design of experiments, independent variables are either noise variables or control variables. In the model presented, the independent variables are further divided into four categories (internal, external, process, and problem) in the group decision making model as a way to help develop an exhaustive list of independent variables affecting the decision making process. The generalized methodology for CGDSA evaluation mapped directly to the computer-aided group decision making model. Solution quality is measured directly or by measuring independent variables that have been previously been correlated to solution quality using standard design of experiment techniques. The generalized methodology for CGDSA evaluation was applied to the assessment of ConsensusBuilder, an example of a CGDSA. As prescribed by the CGDSA evaluation methodology, usability was also assessed and practical use considerations were followed when designing the evaluation. The value of the ConsensusBuilder evaluation for this research was that it was possible to perform a thorough evaluation of ConsensusBuilder, a CGDSA, using the CGDSA Evaluation Methodology developed in this research. In addition to the ConsensusBuilder evaluation, six different CGDSA evaluations cited in the literature were assessed in terms of the CGDSA evaluation methodology

Tests on Models of Nuclear Reactor Elements - Head Losses in Core Sub-Assemblies

Losses have been determined for flow through models of various proposed core sub-assemblies as part of a study of the elements of a nuclear reactor. Six core sections and two? axial blanket sub-assemblies have been compared on the basis of drop in piezometric. head or pressure drop. The core sub-assemblies are composed of an entrance nozzle, a lower axial blanket section, the core section, an upper axial blanket section, and a short section for the handling lug. The four parts of the sub-assembly other than the core section are designated as the axial blanket sub-assembly. In each core section there are 144 rods within a container which has a square cross-section. The primary differences between one core section and another are the means qf supporting and spacing the rods. Bars or wires wrapped in spirals around the rods were used as well as a series of grids made up of wires and supported at the four corners. Also, in one core an, inner wall was used to provide an annular flow passage which helps to reduce the difference in temperature at the inner and outer walls of the core. The two axial blanket sub-assemblies tested are similar except ?that the second model is characterized by more gradual transitions in changes of cross section. Other parts of this study of the elements of a nuclear reactor have been described in two previous reports dealing with head losses in complete blanket subassemblies and with diffusion studies

Tests on Models of Nuclear Reactor Elements - Head Losses in Core Sub-Assemblies

Losses have been determined for flow through models of various proposed core sub-assemblies as part of a study of the elements of a nuclear reactor. Six core sections and two? axial blanket sub-assemblies have been compared on the basis of drop in piezometric. head or pressure drop. The core sub-assemblies are composed of an entrance nozzle, a lower axial blanket section, the core section, an upper axial blanket section, and a short section for the handling lug. The four parts of the sub-assembly other than the core section are designated as the axial blanket sub-assembly. In each core section there are 144 rods within a container which has a square cross-section. The primary differences between one core section and another are the means qf supporting and spacing the rods. Bars or wires wrapped in spirals around the rods were used as well as a series of grids made up of wires and supported at the four corners. Also, in one core an, inner wall was used to provide an annular flow passage which helps to reduce the difference in temperature at the inner and outer walls of the core. The two axial blanket sub-assemblies tested are similar except ?that the second model is characterized by more gradual transitions in changes of cross section. Other parts of this study of the elements of a nuclear reactor have been described in two previous reports dealing with head losses in complete blanket subassemblies and with diffusion studies

Bounds, breaks and unit root tests

The paper addresses the unit root testing when the range of the time series is limited and considering the presence of multiple structural breaks. The structural breaks can affect the level and/or the boundaries of the time series. The paper proposes five unit root test statistics, whose limiting distribution is shown to depend on the number and position of the structural breaks. The performance of the statistics is investigated by means of Monte Carlo simulations

A parameterized approach to modeling and forecasting mortality

A new method is proposed of constructing mortality forecasts. This parameterized approach utilizes Generalized Linear Models (GLMs), based on heteroscedastic Poisson (non-additive) error structures, and using an orthonormal polynomial design matrix. Principal Component (PC) analysis is then applied to the cross-sectional fitted parameters. The produced model can be viewed either as a one-factor parameterized model where the time series are the fitted parameters, or as a principal component model, namely a log-bilinear hierarchical statistical association model of Goodman [Goodman, L.A., 1991. Measures, models, and graphical displays in the analysis of cross-classified data. J. Amer. Statist. Assoc. 86(416), 1085–1111] or equivalently as a generalized Lee–Carter model with p interaction terms. Mortality forecasts are obtained by applying dynamic linear regression models to the PCs. Two applications are presented: Sweden (1751–2006) and Greece (1957–2006)

Sinking properties of some phytoplankton shapes and the relation of form resistance to morphological diversity of plankton – an experimental study

Form resistance (Phi) is a dimensionless number expressing how much slower or faster a particle of any form sinks in a fluid medium than the sphere of equivalent volume. Form resistance factors of PVC models of phytoplankton sinking in glycerin were measured in a large aquarium (0.6 x 0.6 x 0.95 m). For cylindrical forms, a positive relationship was found between Phi and length/ width ratio. Coiling decreased Phi in filamentous forms. Form resistance of Asterionella colonies increased from single cells up to 6-celled colonies than remained nearly constant. For Fragilaria crotonensis chains, no such upper limit to Phi was observed in chains of up to 20 cells ( longer ones were not measured). The effect of symmetry on Phi was tested in 1 - 6-celled Asterionella colonies, having variable angles between the cells, and in Tetrastrum staurogeniaeforme coenobia, having different spine arrangements. In all cases, symmetric forms had considerably higher form resistance than asymmetric ones. However, for Pediastrum coenobia with symmetric/asymmetric fenestration, no difference was observed with respect to symmetry. Increasing number and length of spines on Tetrastrum coenobia substantially increased Phi. For a series of Staurastrum forms, a significant positive correlation was found between arm-length/cell-width ratio and Phi: protuberances increased form resistance. Flagellates (Rhodomonas, Gymnodinium) had a Phi 1. The highest value ( Phi = 8.1) was established for a 20-celled Fragilaria crotonensis chain. Possible origin of the so-called 'vital component' ( a factor that shows how much slower viable populations sink than morphologically similar senescent or dead ones) is discussed, as is the role of form resistance in evolution of high diversity of plankton morphologies

Understanding psychiatric institutionalization: a conceptual review

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited