Estimating the Size of a Criminal Population from Police Records Using the Truncated Poisson Regression Model

The truncated Poisson regression model is used to arrive at point and interval estimates of the size of two offender populations, i.e. drunk drivers and persons who illegally possess firearms. The dependent capture–recapture variables are constructed from Dutch police records and are counts of individual arrests for both violations. The population size estimates are derived assuming that each count is a realization of a Poisson distribution, and that the Poisson parameters are related to covariates through the truncated Poisson regression model. These assumptions are discussed in detail, and the tenability of the second assumption is assessed by evaluating the marginal residuals and performing tests on overdispersion. For the firearms example, the second assumption seems to hold well, but for the drunk drivers example there is some overdispersion. It is concluded that the method is useful, provided it is used with care.     

Consistent estimation in the bilinear multivariate errors-in-variables model

A bilinear multivariate errors-in-variables model is considered. It corresponds to an overdetermined set of linear equations AXB=C, A∈ℝ^m×n, B∈ℝ^p×q, in which the data A, B, C are perturbed by errors. The total least squares estimator is inconsistent in this case.  An adjusted least squares estimator is constructed, which converges to the true value X, as m →∞, q →∞. A small sample modification of the estimator is presented, which is more stable for small m and q and is asymptotically equivalent to the adjusted least squares estimator. The theoretical results are confirmed by a simulation study. Acknowledgements. We thank two anonymous reviewers for their suggestions and corrections.? A. Kukush is supported by a postdoctoral research fellowship of the Belgian office for Scientific, Technical and Cultural Affairs, promoting Scientific and Technical Collaboration with Central and Eastern Europe.? S. Van Huffel is a full professor with the Katholieke Universiteit Leuven.? I. Markovsky is a research assistant with the Katholieke Universiteit Leuven.? This paper presents research results of the Belgian Programme on Interuniversity Poles of Attraction (IUAP V-22), initiated by the Belgian State, Prime Minister's Office – Federal Office for Scientific, Technical and Cultural Affairs of the Concerted Research Action (GOA) projects of the Flemish Government MEFISTO-666 (Mathematical Engineering for Information and Communication Systems Technology), of the IDO/99/03 project (K.U. Leuven) “Predictive computer models for medical classification problems using patient data and expert knowledge”, of the FWO projects G.0078.01, G.0200.00, and G0.0270.02.? The scientific responsibility is assumed by its authors.     

Demand for durable and nondurable goods,environmental policy and consumer welfare

If a tax on energy affects the demand for a nondurable good, the stock of a durable good, and the proportion of the energy consumption per unit of service of the durable good, an integrated approach for investigating consumer demand for durables and nondurables is required. The purpose of this paper is to employ the concept of a variable expenditure function with quasi-fixed durable goods as arguments in order to derive a demand system for nondurable goods in prices of the nondurables, in the stocks of durables, and in variable expenditure. From the envelope condition desired stocks of durables can be calculated and investment demand for durables can be determined. For an application we choose a variable expenditure function based on the almost ideal demand specification, and evaluate alternative environmental policy measures using the equivalent variation for comparing the welfare effects.     

Development and the mystification of ‘cultural factors’: One destiny: Our common future in Africa,by A S van Niekerk

In One destiny: Our common future in Africa the author relates, in popular fashion, a series of incidents which convinced him that the basic difference between black and white in South Africa is cultural deep‐seated and the cause of underdevelopment and conflict He develops a circular argument in which world‐view is taken as the root of perceptions, values and activities. The effects of experience and economic and political factors are given secondary importance. This argument cannot accommodate social change and differentiation, and the author tends to concentrate on perceptions and events which he finds morally unacceptable. He gives an unbalanced assessment and an ethnocentric interpretation of African life. Possible reasons for this type of argument are explored and an alternative which takes its departure from the interaction between experience and perception is offered     

There's something about saving …

The paper considers how people should plan their saving, given certain assumptions about inheritance and changes in household circumstances. The results are produced by a model that takes into account tax and state benefits as well as various private savings vehicles. It concludes that, for many households, saving for retirement through a ‘pension’ might not be optimum and that the best strategy is to vary the incidence and allocation of saving in response to changes in household circumstances.     

Satisfaction drivers for Internet service technology among stock brokerage customers in Thailand

Many financial services firms are offering the Internet as a self-service technology (SST), for online stock trading, in an effort to increase effciency and give customers greater access. It is important to understand how this technology will influence customer satisfaction. This paper reports results of exploratory research to identify sources of customer satisfaction and dissatisfaction with the service encounter in Thai stockbrokerage firms. Results show that customers and service providers determine sources of customer dis/satisfaction differently, depending on whether the service encounter is technology-based or interpersonal. Different customer profiles give rise to segmentation in response to the use of Internet technology in this industry.     

Permanent magnets: a technological analysis

Abstract
Technology analysis is a new technomanagerial discipline that provides common frameworks for analysing individual technologies and their relationships to each other. It is used here to probe the development of a particular technology, namely that of permanent magnets.
The paper traces the development of permanent magnets over the past decade and explores possible future improvements in performance parameters. The strength of magnets (i.e. energy product as expressed in kilo Joules per cubic metre) has increased from approximately 40 in the 1930s to approximately 400 at present.
Future developments will be constrained by a barrier which seems to exist at approximately 525 kilo Joules per cubic metre. However this is viewed as a barrier that can be transcended and not as an immutable limit. It therefore signifies a possible breakthrough zone.
S-curve theory leads analysts to speculate about a possible breakthrough during the five year period leading up to 1995. At that date magnetic strengths of 600+ kilo Joules per cubic metre could be aimed for.
Increased magnetic strength will improve the performance parameters of all technologies utilising magnets, unleash new magnetic based technologies and threaten many traditional areas in the fields of matter processing, transporting and storing, energy processing, and information processing and storing.
These effects will cascade through the entire technological landscape creating new markets and destroying others. The article gives an overview of these impacts on the technological landscape.     

Optimality conditions¶and bubbles in sequential economies¶and bounded relative risk-aversion

We provide specific qualifications in order that Kuhn–Tucker type Euler equations and transversality conditions at infinity hold in stochastic equilibrium models with heterogeneous agents and where assets are traded in sequential markets. It is not assumed that uncertainty is modeled as an event-tree structure or that preferences are necessarily bounded. We also describe an important class of preferences based on bounded relative risk aversion which yields relevant simplifications. Our results are used to establish conditions that rule out asset pricing bubbles. Specific examples of economies with bubbles are also discussed. Received: 28 January 2002 / Accepted: 19 July 2002 We are grateful to the editor and an anonymous referee for their valuable comments. This research was partially supported by MURST (Italy), National Group on “Nonlinear Dynamics and Stochastic Models in Economics and Finance”.