A Geometric Approach to Nonlinear Econometric Models

Conventional tests for composite hypotheses in minimum distance models can be unreliable when the relationship between the structural and reduced‐form parameters is highly nonlinear. Such nonlinearity may arise for a variety of reasons, including weak identification. In this note, we begin by studying the problem of testing a “curved null” in a finite‐sample Gaussian model. Using the curvature of the model, we develop new finite‐sample bounds on the distribution of minimum‐distance statistics. These bounds allow us to construct tests for composite hypotheses which are uniformly asymptotically valid over a large class of data generating processes and structural models.     

Lesbian Blood Drives as Community-Building Activism in the 1980s

As gay men began voluntarily withdrawing from blood donation in the early 1980s, lesbians in community with gay men in several U.S. cities organized drives to replenish the blood supply. These drives were sometimes the continuation of previously established drives by gay–lesbian organizations or faith communities, sometimes new initiatives in response to HIV/AIDS. However, after the initial publicity, mention of lesbian blood drives in print is both scarce and brief. Focusing on drives organized from 1983 to 1992 by a group known as San Diego Blood Sisters, this article is an initial step in documenting lesbian blood drives to inform and enrich conversations about histories of responses to HIV/AIDS, theoretical discussions of how community connections in the lesbian, gay, bisexual, transgender, and queer spectrum are enacted and understood, and emerging research on intersections of gender and sexuality as they are expressed through blood donorship.     

Including employees with disabilities in emergency evacuation plans: 9/11's effect on the demand for information

Interest in emergency evacuation planning has increased since the September 11 terrorist attacks (9/11). In turn, the Job Accommodation Network (JAN) started receiving more questions about how to include employees with disabilities in such plans. JAN case data on the emergency evacuation of people with disabilities were reviewed. Case data from the four years prior to 9/11 (from September 11, 1997, to September 11, 2001) were compared to case data from the four years after 9/11 (from September 11, 2001, to September 11, 2005).     

High wage workers and low wage firms: negative assortative matching or limited mobility bias?

Summary.  In the empirical literature on assortative matching using linked employer–employee data, unobserved worker quality appears to be negatively correlated with unobserved firm quality. We show that this can be caused by standard estimation error. We develop formulae that show that the estimated correlation is biased downwards if there is true positive assortative matching and when any conditioning covariates are uncorrelated with the firm and worker fixed effects. We show that this bias is bigger the fewer movers there are in the data, which is 'limited mobility bias'. This result applies to any two-way (or higher) error components model that is estimated by fixed effects methods. We apply these bias corrections to a large German linked employer–employee data set. We find that, although the biases can be considerable, they are not sufficiently large to remove the negative correlation entirely.     

Understanding Unique Effects of Parental Incarceration on Children: Challenges,Progress, and Recommendations

Growth in U.S. incarceration rates during the 1980s and 1990s prompted a body of research focused on understanding the diverse effects of incarceration on individuals, families, and communities. An area of particular interest has been how the incarceration of a parent may affect child well‐being. Despite what appears to be converging evidence that parental incarceration poses a significant threat to child development, this area of inquiry has yet to overcome important methodological and conceptual challenges related to selection bias. It is therefore unclear whether the difficulties that have been observed among children whose parents are incarcerated are due to the incarceration itself or to other adversities that children have experienced. The purpose of this article is to draw attention to these issues, to summarize empirical and conceptual progress in overcoming these challenges, and to suggest directions for future research.     

Wheeling uphill? Reflections of practical and methodological difficulties encountered in researching the experiences of disabled volunteers

This paper focuses on methodological and practical issues surrounding research into disabled volunteers. It focuses on three key methodological and practical issues which were encountered by the author in preparing for and conducting fieldwork: difficulties in conceptualising disability for the purpose of the study; problems of access; and problems of reflexivity. Attention is also given to how the researcher responded to the problems and difficulties as they emerged throughout the research. The paper concludes by commenting that the overall commitment, social entrepreneurship and social advocacy of wheelchair users who volunteer is in stark contrast to the negative images of vulnerability and dependency often associated with disability.     

An Unacceptable Role for Social Work: Implementing Immigration Policy

Correspondence to Dr Beth Humphries, Department of Applied Social Science, Lancaster University, Cartmel College, Lancaster, LA1 4YL. E-mail: b.humphries{at}lancaster.ac.uk Summary Social work has always had a role in policing the boundariesof welfare, and under New Labour there has been a decisive shiftto an increasingly narrow and negative practice. This articletakes social work’s involvement in internal immigrationcontrols as an example of the profession’s complicityin implementing social policies that are degrading and inhuman.It argues that social work has adopted a reactionary and uncriticalview of policy, and asks whether there might be a more progressivefuture for the profession.     

A Three‐step Method for Choosing the Number of Bootstrap Repetitions

This paper considers the problem of choosing the number of bootstrap repetitions B for bootstrap standard errors, confidence intervals, confidence regions, hypothesis tests, p‐values, and bias correction. For each of these problems, the paper provides a three‐step method for choosing B to achieve a desired level of accuracy. Accuracy is measured by the percentage deviation of the bootstrap standard error estimate, confidence interval length, test's critical value, test's p‐value, or bias‐corrected estimate based on B bootstrap simulations from the corresponding ideal bootstrap quantities for which B=∞. The results apply quite generally to parametric, semiparametric, and nonparametric models with independent and dependent data. The results apply to the standard nonparametric iid bootstrap, moving block bootstraps for time series data, parametric and semiparametric bootstraps, and bootstraps for regression models based on bootstrapping residuals. Monte Carlo simulations show that the proposed methods work very well.     

Barriers and Facilitators to Implementing Functional Family Therapy in a Community Setting: Client and Practitioner Perspectives

While Functional Family Therapy (FFT) is known to be effective in addressing adolescent behavioral problems, there has been little exploration of issues relevant to its transport from the tightly controlled setting of clinical trials into routine service delivery. This study sought the views of key stakeholders, clients, and practitioners, on barriers and facilitators to the successful implementation of FFT. Undertaken in a community setting in Scotland, interviews were carried out with 12 adolescents, 14 parents/caregivers, and 6 practitioners. Results focus on: Referral process and pre‐intervention contact; Engagement of families; Structure and delivery; Organizational factors. Although barriers to engagement were identified, FFT was viewed as an acceptable, appropriate and feasible intervention with the potential to improve adolescent wellbeing in ‘real‐world’ settings.