Bayesian Analysis of an Unobserved-Component Time Series Model of GDP With Markov-Switching and Time-Varying Growths

We propose an unobserved-component time series model of gross domestic product that includes Markov switching as an unobserved component. In addition to a trend component, the model has two time-varying drift components. One drift represents the expected rate of growth during recession; the other drift represents the expected rate during expansion. Estimates indicate a substantial decline in the latter annual rate for the United States from 6.4% in 1950 to 3.6% by 1990. We have employed weak priors based on prewar data. The estimation makes use of the Gibbs sampler and the Metropolis algorithm.     

A new approach to investigating spatial variations of disease

Summary.  For rare diseases the observed disease count may exhibit extra Poisson variability, particularly in areas with low or sparse populations. Hence the variance of the estimates of disease risk, the standardized mortality ratios, may be highly unstable. This overdispersion must be taken into account otherwise subsequent maps based on standardized mortality ratios will be misleading and, rather than displaying the true spatial pattern of disease risk, the most extreme values will be highlighted. Neighbouring areas tend to exhibit spatial correlation as they may share more similarities than non-neighbouring areas. The need to address overdispersion and spatial correlation has led to the proposal of Bayesian approaches for smoothing estimates of disease risk. We propose a new model for investigating the spatial variation of disease risks in conjunction with an alternative specification for estimates of disease risk in geographical areas—the multivariate Poisson–gamma model. The main advantages of this new model lie in its simplicity and ability to account naturally for overdispersion and spatial auto-correlation. Exact expressions for important quantities such as expectations, variances and covariances can be easily derived.     

Bivariate prior distributions via branching exchangeable sequences

This paper provides a novel approach to constructing bivariate prior distributions. The idea is based on the notion of partial exchangeability. In particular, in a simple extension of the exchangeable sequence, we create two dependent exchangeable sequences via a branching mechanism. This implies the existence of a bivariate prior distribution.     

How to take a penalty

When Rob Eastaway told friends he was embarking on a project to write a book about the maths of sport, they didn't hear the word "maths"-they heard "statistics". That, after all, is the most obvious interpretation. But, as he discovered, mechanics, geometry and even some mathematical history all play their part.     

Human Interindividual Variability in Parameters Related to Health Risks

This paper reviews existing data on the variability in parameters relevant for health risk analyses. We cover both exposure-related parameters and parameters related to individual susceptibility to toxicity. The toxicity/susceptibility data base under construction is part of a longer term research effort to lay the groundwork for quantitative distributional analyses of non-cancer toxic risks. These data are broken down into a variety of parameter types that encompass different portions of the pathway from external exposure to the production of biological responses. The discrete steps in this pathway, as we now conceive them, are:Contact Rate (Breathing rates per body weight; fish consumption per body weight)Uptake or Absorption as a Fraction of Intake or Contact RateGeneral Systemic Availability Net of First Pass Elimination and Dilution via Distribution Volume (e.g., initial blood concentration per mg/kg of uptake)Systemic Elimination (half life or clearance)Active Site Concentration per Systemic Blood or Plasma ConcentrationPhysiological Parameter Change per Active Site Concentration (expressed as the dose required to make a given percentage change in different people, or the dose required to achieve some proportion of an individual's maximum response to the drug or toxicant)Functional Reserve Capacity–Change in Baseline Physiological Parameter Needed to Produce a Biological Response or Pass a Criterion of Abnormal FunctionComparison of the amounts of variability observed for the different parameter types suggests that appreciable variability is associated with the final step in the process–differences among people in functional reserve capacity. This has the implication that relevant information for estimating effective toxic susceptibility distributions may be gleaned by direct studies of the population distributions of key physiological parameters in people that are not exposed to the environmental and occupational toxicants that are thought to perturb those parameters. This is illustrated with some recent observations of the population distributions of Low Density Lipoprotein Cholesterol from the second and third National Health and Nutrition Examination Surveys.     

'Out of Place', 'Knowing One's Place': space, power and the exclusion of disabled people

Disabled people are marginalised and excluded from 'mainstream' society. In general, our understanding of the processes of exclusion is grounded in time and history. In this paper, it is argued that space, as well as time, is instrumental in reproducing and sustaining disablist practices. Disability has distinct spatialities that work to exclude and oppress disabled people. Spaces are currently organised to keep disabled people 'in their place' and 'written' to convey to disabled people that they are 'out of place'. Furthermore, social relations currently work to spatially isolate and marginalise disabled people and their carers. Disability is spatially, as well as socially, constructed. It is contended that an understanding of society's reaction to, and the experiences of, disability should be framed within an approach that combines a spatialised political economy with social constructivism. Unlike neo-Marxist approaches this approach is centred on notions of power rather than capital. Using this approach, the spatialities of disability are explored.     

On the Margins: disabled people's experience of employment in Donegal, West Ireland

Traditionally, studies of disabled people's access to the labour market have been largely restricted to labour market 'censuses', often conducted by government agencies, and econometric studies. This paper explores disabled people's access to and experiences of employment in Donegal, West Ireland, using a qualitative approach. Twelve disabled people and four non-disabled helpers, divided into two focus groups, were interviewed using an in-depth, informal conversational strategy. A number of different, salient issues were identified in regards to training, and gaining and maintaining employment, ranging from ignorance and discrimination, to poor access (both workplace and transport), to legislation. Respondents identified a number or potential solutions which mainly focused around disability awareness, removing barriers to gaining employment and the implementation of stronger legislation. In the final section, the issues and solutions raised by disabled people are compared to those identified by non-disabled people, collected in a parallel study.