The Marshallian macroeconomic model: A progress report

In this progress report, we first indicate the origins and early development of the Marshallian macroeconomic model (MMM) and briefly review some of our past empirical forecasting experiments with the model. Then we present recently developed one-sector, two-sector and n-sector models of an economy that can be employed to explain past experience, predict future outcomes and analyze policy problems. The results of simulation experiments with various versions of the model are provided to illustrate some of its dynamic properties that include “chaotic” features. Last, we present comments on planned future work with the model.     

Software for Learning and for Doing Statistics

The community of statisticians and statistics educators should take responsibility for the evaluation and improvement of software quality from the perspective of education. The paper will develop a perspective, an ideal system of requirements to critically evaluate existing software and to produce future software more adequate both for learning and doing statistics in introductory courses. Different kinds of tools and microworlds are needed. After discussing general requirements for such programs, a prototypical ideal software system will be presented in detail. It will be illustrated how such a system could be used to construct learning environments and to support elementary data analysis with exploratory working style.     

A note on “Bed allocation techniques based on census data”

Capacity planning and resource allocation are crucial to the cost-effective delivery of health care services. In this paper, we present an analytic approach based on a modified version of the Holt-Winters multiplicative seasonality forecasting model to determine the frequency distribution associated with a hospital care unit's census. This paper is a follow-up to the census frequency distribution simulation model described in Lapierre et al. (Socio Econ. Plan. Sci. 33 (1999) 25). We demonstrate that our model can provide census frequency distributions equivalent to the simulation model of Lapierre et al. [1], but without the computational effort common to simulation models.     

The adequacy of asymptotic approximations in the near-integrated autoregressive model with dependent errors

We consider the normalized least squares estimator of the parameter in a nearly integrated first-order autoregressive model with dependent errors. In a first step we consider its asymptotic distribution as well as asymptotic expansion up to order O_p(T⁻¹). We derive a limiting moment generating function which enables us to calculate various distributional quantities by numerical integration. A simulation study is performed to assess the adequacy of the asymptotic distribution when the errors are correlated. We focus our attention on two leading cases: MA(1) errors and AR(1) errors. The asymptotic approximations are shown to be inadequate as the MA root gets close to −1 and as the AR root approaches either −1 or 1. Our theoretical analysis helps to explain and understand the simulation results of Schwert (1989) and DeJong, Nankervis, Savin, and Whiteman (1992) concerning the size and power of Phillips and Perron's (1988) unit root test. A companion paper, Nabeya and Perron (1994), presents alternative asymptotic frameworks in the cases where the usual asymptotic distribution fails to provide an adequate approximation to the finite-sample distribution.     

MANAGING VENDOR INVENTORY IN A DUAL LEVEL DISTRIBUTION SYSTEM

Collaborative arrangements among members of the supply chain have received a great deal of interest in recent years as a means of reducing costs. One such arrangement is vendor managed inventory (VMI). VMI allows the vendor to make decisions concerning the quantity and timing of deliveries to the retailer. Such an arrangement offers the potential of a more efficient supply chain by removing the negative effects of retail ordering policies. A thorough review of the literature was conducted to identify factors likely to impact the performance of a VMI partnership. Computer simulation was used to study the effects of these factors from both the vendor's and retailer's perspectives. The results lend insight into the performance of VMI and guidance for managers as to the environments in which VMI is most effective.     

Progressive stress accelerated life tests under finite mixture models

In this paper, progressive stress accelerated life tests are considered when the lifetime of a product under use condition follows a finite mixture of distributions. The experiment is performed when each of the components in the mixture follows a general class of distributions which includes, among others, the Weibull, compound Weibull, power function, Gompertz and compound Gompertz distributions. It is assumed that the scale parameter of each component satisfies the inverse power low, the progressive stress is directly proportional to time and the cumulative exposure model for the effect of changing stress holds. Based on type-I censoring, the maximum likelihood estimates (MLEs) of the parameters under consideration are obtained. A special attention is paid to a mixture of two Rayleigh components. Simulation results are carried out to study the precision of the MLEs and to obtain confidence intervals for the parameters involved.     

The Bank of England quarterly model of the UK economy

The Bank of England first acquired a macroeconomic model of the UK economy in early 1973, and used it for forecasting in June and July of that year. The initial model was obtained from the London Business School (LBS), but the last 14 years or so have, on the part of both the Bank and the LBS, led to developments which now make the models no closer to each other than to other large scale models of the UK. This article describes the structure and central properties of the current version of the Bank model, which has some 663 variables, 134 of which are modelled by behavioural equations, 153 by technical equations, 212 identities and 164 exogenous variables. In order to provide a transitional step between the kind of models with which most macroeconomists are familiar and the full scale version of the Bank model, one part of the article presents a very simple stylized version of the full model. This is a stepping stone to the full model which is described and analysed on a sectoral basis in Part 3, with a complete listing of equations in Part 4. Some of the simulation properties, and hence full model dynamic responses, are considered in Part 5.     

An analysis of the process generating de facto standards in the PC spreadsheet software market

This paper develops a model to analyze the emergence of de facto or market defined compatibility standards in the market for PC spreadsheet software over the period 1982–1988. The model is capable of integrating diverse fragments of empirical evidence and a number of important theoretical building blocks, in particular the analysis of gateways between different versions of the same package, product preannouncements, and diverse consumer tastes towards intrinsic quality and network externalities. The model also explores the implications of different functional forms for the relationship between installed base and the value of network externalities. The paper finds that at least some enhancements to the basic model of standards have to be incorporated to offer a reasonable approximation to developments in the PC spreadsheet software market. The simplest model of de facto standards is not able to describe developments in this market.     

Werbewirkung durch Imagery-Processing

Zusammenfassung Die Frage, warum bestimmte Informationen oder Werbemittel mehr und andere weniger Überzeugungskraft aufweisen, beschäftigt die Marketingforschung und verwandte Gebiete schon seit geraumer Zeit. Eine dieser Thematik zuzuordnende Forschungsrichtung, die in den letzten zwanzig Jahren eine Forschungstradition entwickelte, ist die Imagery-Forschung. Autoren, die sich dieser Forschungsrichtung zuwenden, erklären die Wirkung von Informationen damit, dass die Elemente in dieser Information Gedächtnisinhalte oder Imaginationen (Fantasien bzw. Vorstellungen) bei den Rezipienten auslösen, die ihrerseits die Bewertung des relevanten Meinungs- oder Werbeobjekts beeinflussen. In diesem Beitrag wird zunächst dargestellt, welche Hypothesen im Mittelpunkt der neueren Imagery-Forschung stehen. Der Nutzen dieser Überlegungen besteht zum Beispiel für die Werbepraxis darin, dass konkrete Hinweise für die Werbegestaltung gegeben werden. Anschließend wird der Stand der empirischen Forschung zu diesen Hypothesen vorgestellt. Hier zeigt sich, dass die empirischen Erkenntnisse hinter dem Stand der theoretischen Forschung zurückgeblieben sind. Am Ende dieser Abhandlung werden Vorschläge unterbreitet, wie die theoretischen Überlegungen einer weitergehenden Analyse unterzogen werden können. JEL classifications M31, M37     

Seasonality and Markov switching in an unobserved component time series model

It is generally acknowledged that the growth rate of output, the seasonal pattern, and the business cycle are best estimated simultaneously. To achieve this, we develop an unobserved component time series model for seasonally unadjusted US GDP. Our model incorporates a Markov switching regime to produce periods of expansion and recession, both of which are characterized by different underlying growth rates. Although both growth rates are time-varying, they are assumed to be cointegrated. The analysis is Bayesian, which fully accounts for all sources of uncertainty. Comparison with results from a similar model for seasonally adjusted data indicates that the seasonal adjustment of the data significantly alters several aspects of the full model. First Version Received: January 2001/Final Version Received: February 2002 Send offprint requests to: Rob Luginbuhl?Correspondence to: Rob Luginbuhl