Constrained Monotonicity and the Measurement of Power

In this paper we will discuss constraints on the number of (non-dummy) players and on the distribution of votes such that local monotonicity is satisfied for the Public Good Index. These results are compared to properties which are related to constraints on the redistribution of votes (such as implied by global monotonicity). The discussion shows that monotonicity is not a straightforward criterion of classification for power measures. This revised version was published online in June 2006 with corrections to the Cover Date.     

Sample size determination of steel's nonparametric many-one test

We derive sample size formulas for the many-one test of Steel (1959) when the all-pairs power is preassigned. In this large sample approach we replace, similar to Noether (1987), the unknown variances and also the unknown correlation coefficients in the power expressions by their known values under the null hypotheses. We then obtain least favorable configurations for one-and two-sided comparisons. The reliability of our formulas is examined in computer simulations for different alternatives with various distributions.     

Can oil-led growth and structural change go hand in hand in Ghana?

Unlike in Asia, the manufacturing sector has not (yet) become a driver of structural change in Africa. One common explanation is that the natural resource-focus of many African economies leads to Dutch disease effects. To test this argument for the case of newly found oil in Ghana we develop a multi-sector intertemporal general equilibrium model with endogenous savings and investment behavior. Results show that in addition to the well-known short-term Dutch disease effects, long-term structural effects can indeed impede Asian-style economic transformation in Ghana (and other resource rich countries). We also demonstrate how oil wealth may go hand in hand with structural change in the future.     

Mental Models in Risk Assessment: Informing People About Drugs

One way to communicate about the risks of drugs is through the use of package inserts. The problems associated with this medium of informing patients have been investigated by several researchers who found that people require information about drugs they are using, including extensive risk information, and that they are willing to take this information into account in their usage of drugs. But empirical results also show that people easily misinterpret the information given. A conceptual framework is proposed that might be used for better understanding the cognitive processes involved in such a type of risk assessment and communication. It is based on the idea that people develop, through experience, a mental model of how a drug works, which effects it might produce, that contraindications have to be considered, etc. This mental model is "run" when a specific package insert has been read and a specific question arises such as, for example, whether certain symptoms can be explained as normal or whether they require special attention and action. We argue that the mental model approach offers a useful perspective for examining how people understand package inserts, and consequently for improving their content and design. The approach promises to be equally useful for other aspects of risk analysis that are dependent upon human judgment and decision making, e.g., threat diagnosis and human reliability analysis.     

Assessing children's relationships with pet dogs: A multi-method approach

Relationships with pet dogs are thought to provide substantial benefits for children, but the study of these relationships has been hindered by a lack of validated measures. Approaches to assessing the quality of children's pet dog relationships have tended to focus on positive relationship qualities and to rely on self-report questionnaires. The aim of this study was to develop and test multiple measures that could be used to assess both positive and negative features of children's relationships with pet dogs. In a sample of 115 children ages 9–14 years who were pet dog owners, we assessed six qualities of pet dog relationships: Affection, Nurturance of Pet, Emotional Support from Pet, Companionship, Friction with Pet, and Pets as Substitutes for People. All qualities were assessed with child questionnaires, parent questionnaires, and child daily reports of interactions with pets. We found substantial convergence in reports from different observers and across different measurement approaches. Principal components analyses and correlations suggested overlap for many of the positive qualities, which tended to be distinct from negative relationship qualities. The study provides new tools which could be used to test further how relationships with pets contribute to children's development.     

Editorial special issue: Statistics in sports

AStA Advances in Statistical Analysis - Triggered by advances in data gathering technologies, the use of statistical analyzes, predictions and modeling techniques in sports has gained a rapidly...     

Introducing LASSO-type penalisation to generalised joint regression modelling for count data

AStA Advances in Statistical Analysis - In this work, we propose an extension of the versatile joint regression framework for bivariate count responses of the R package GJRM by Marra and Radice (R...     

Influences of landscape structure on butterfly diversity in urban private gardens using a citizen science approach

Urban Ecosystems - Although urbanization is increasing worldwide, private gardens may help mitigate the impact of urbanization on butterfly diversity. We investigated how local and landscape...