Requests, Blocking Moves, and Rational (Inter)action in Survey Introductions

We draw on conversation analytic methods and research to explicate the interactional phenomenon of requesting in general and the specific case of requesting participation in survey interviews. Recent work on survey participation has given much attention to leverage-saliency theory, but has not engaged how the key concepts of this theory are exhibited in the actual unfolding interaction of interviewers and potential respondents. We do so using digitally recorded and transcribed calls to recruit participation in the 2004 Wisconsin Longitudinal Study. We describe how potential respondents present interactional environments that are relatively discouraging or encouraging, and how, in response, interviewers may be relatively cautious or presumptive in their requesting actions. We consider how the ability of interviewers to tailor their behavior to their interactional environment can affect whether the introduction reaches the point at which a request to participate is made, the form that this request takes, and the sample person's response. Our analysis contributes to understanding how we might use insights from the analysis of interaction to increase cooperation with requests to participate in surveys.     

Dropping out of university: A statistical analysis of the probability of withdrawal for UK university students

From individual level data for an entire cohort of undergraduate students in the 'old' universities in the UK, we use a binomial probit model to estimate the probability that an individual will 'drop out' of university before the completion of their degree course. We examine the cohort of students enrolling full time for a 3- or 4-year degree in the academic year 1989–1990. We find evidence to support both the hypothesis that the completion of courses by students is influenced by the extent of prior academic preparedness and the hypothesis that social integration at university is important. We also find an influence of unemployment in the county of prior residence, especially for poorer male students. Finally, we draw conclusions regarding the public policy of constructing university performance indicators in this area.     

Probabilistic sensitivity analysis of complex models: a Bayesian approach

Summary.  In many areas of science and technology, mathematical models are built to simulate complex real world phenomena. Such models are typically implemented in large computer programs and are also very complex, such that the way that the model responds to changes in its inputs is not transparent. Sensitivity analysis is concerned with understanding how changes in the model inputs influence the outputs. This may be motivated simply by a wish to understand the implications of a complex model but often arises because there is uncertainty about the true values of the inputs that should be used for a particular application. A broad range of measures have been advocated in the literature to quantify and describe the sensitivity of a model's output to variation in its inputs. In practice the most commonly used measures are those that are based on formulating uncertainty in the model inputs by a joint probability distribution and then analysing the induced uncertainty in outputs, an approach which is known as probabilistic sensitivity analysis. We present a Bayesian framework which unifies the various tools of prob- abilistic sensitivity analysis. The Bayesian approach is computationally highly efficient. It allows effective sensitivity analysis to be achieved by using far smaller numbers of model runs than standard Monte Carlo methods. Furthermore, all measures of interest may be computed from a single set of runs.     

Models for residual time to AIDS

The distributions of the time from Human Immunodeficiency Virus (HIV) infection to the onset of Acquired Immune Deficiency Syndrome (AIDS) and of the residual time to AIDS diagnosis are important for modeling the growth of the AIDS epidemic and for predicting onset of the disease in an individual. Markers such as CD4 counts carry valuable information about disease progression and therefore about the two survival distributions. Building on the framework set out by Jewell and Kalbfleisch (1992), we study these two survival distributions based on stochastic models for the marker process (X(t)) and a marker-dependent hazard (h()). We examine various plausible CD4 marker processes and marker-dependent hazard functions for AIDS proposed in recent literature. For a random effects plus Brownian motion marker process X(t)=(a+bt+BM(t))⁴, where a has a normal distribution, b<0 is an unknown parameter and BM(t) is Brownian motion, and marker-dependent hazard h(X(t)), we prove that, given CD4 cell count X(t), the residual time to AIDS distribution does not depend on the time since infection t. Using simulation and numerical integration, we find the marginal incubation period distribution, the marginal hazard and the residual time distribution for several combinations of marker processes and marker-dependent hazards. An example using data from the Multicenter AIDS Cohort Study is given. A simple regression model relating the cube root of residual time to AIDS to CD4 count is suggested.     

Unpacking the terms of engagement with local food at the Farmers’ Market: Insights from Ontario

Amidst much discussion of the values and venues of local food, the Farmers’ Market (FM) has emerged as an important, but somewhat uncertain, site of engagement for producers, consumers and local food ‘champions’. Despite the evident certainty of various operational rules, the FM should be seen as a complex and ambiguous space where (contingent) notions of local, quality, authenticity and legitimacy find expression in communications and transactions around food. This paper seeks to extend current reflections on the nature of the contemporary FM and its relationship to the tenets of local food. An empirical analysis involving sellers, shoppers and managers at 15 markets in the Province of Ontario, Canada sought to understand how participants ‘read’ the market as an operating space and subsequently construct the terms of (their) engagement. Findings suggest that Ontario FM customers wish to support farmers and farming via their food-related spending and express attachments to a wide range of alleged benefits pertaining to local food. Yet these values are also malleable in their meaning and amenable to trade-off against other considerations—particularly where social capital is concerned. The notion of ‘local’ emerges as being widely valued but also highly interpretive in its meaning and variable in its absolute importance. The paper concludes with some reflection on the degree to which the findings support, challenge or modify current normative beliefs about local food at the FM.     

Barack Obama's “American” Problem: Unhyphenated Americans in the 2008 Elections*

Objectives. The largest increase of any ancestry group between the 1990 and 2000 Census in the United States were “unhyphenated Americans,” those whites who claimed an “American” or no ancestry. This article measures this group's voting habits in the 2008 elections. Methods. With individual‐level attitudinal data and county‐level voting data from the 2008 primary and 2000–2008 general elections, the analyses use quantitative methods to estimate unhyphenated Americans' voting behavior. Results. Evidence indicates a strong rejection of Obama among counties with high proportions of unhyphenated Americans in both the 2008 primary and general elections. Conclusion. While spatially concentrated in and near Appalachia, unhyphenated Americans' politics are distinctive irrespective of socioeconomic status, religion, and geography, being one of the few groups in which Barack Obama lost votes compared to previous Democratic nominees. Variation in the share of unhyphenated Americans explains more of the difference between 2008 and past elections than variation in the share of African Americans per county.     

Of Knights, Knaves and Merchants: The Case of Residential Care for Older People in England in the Late 1990s

This paper examines the motivations of a sample of fifty providers of residential care for older people in England in 1997. The theoretical point of departure is the "knights and knaves" categorization suggested by Julian Le Grand. A cluster analysis of the expressed motivations of the providers of residential care suggests three types: empathizers, professionals and income prioritizers. These combine knightly and knavish motives in varying degrees. Le Grand's recommendation that strategic policy towards actors in welfare services should be robust about motives is endorsed. However, a third, "mercantile", aspect of motivation is revealed reflecting providers' needs to exercise control over, and experience ownership of, their enterprises. This should also be taken into account in the design of policy. Policy decisions that are insensitive to this aspect of motivation are likely to be misguided and flawed.     

Evaluating national initiatives: the case of ‘On Track’

On Track is a long‐term crime reduction programme aimed at children at risk of becoming involved in crime. Twenty‐four pilots are being established in deprived communities in England and Wales. In each area a range of evidence‐based preventive services for four to 12 year olds will be developed. There will be intensive inter‐agency cooperation enabling children at risk of offending to be identified early so that they and their families can be provided with consistent services during the child's development. The effectiveness and cost‐effectiveness of the arrangements in each area will be evaluated with a view to finding out more about ‘what works’. Copyright © 2001 John Wiley & Sons, Ltd.     

Moving Average-Based Estimators of Integrated Variance

We examine moving average (MA) filters for estimating the integrated variance (IV) of a financial asset price in a framework where high-frequency price data are contaminated with market microstructure noise. We show that the sum of squared MA residuals must be scaled to enable a suitable estimator of IV. The scaled estimator is shown to be consistent, first-order efficient, and asymptotically Gaussian distributed about the integrated variance under restrictive assumptions. Under more plausible assumptions, such as time-varying volatility, the MA model is misspecified. This motivates an extensive simulation study of the merits of the MA-based estimator under misspecification. Specifically, we consider nonconstant volatility combined with rounding errors and various forms of dependence between the noise and efficient returns. We benchmark the scaled MA-based estimator to subsample and realized kernel estimators and find that the MA-based estimator performs well despite the misspecification.