Detection of multiple undocumented change-points using adaptive Lasso

The problem of detecting multiple undocumented change-points in a historical temperature sequence with simple linear trend is formulated by a linear model. We apply adaptive least absolute shrinkage and selection operator (Lasso) to estimate the number and locations of change-points. Model selection criteria are used to choose the Lasso smoothing parameter. As adaptive Lasso may overestimate the number of change-points, we perform post-selection on change-points detected by adaptive Lasso using multivariate t simultaneous confidence intervals. Our method is demonstrated on the annual temperature data (year: 1902–2000) from Tuscaloosa, Alabama.     

Piece rates and workplace injury: Does survey evidence support Adam Smith?

While piece rates are routinely associated with higher productivity and wages, they can also generate unanticipated effects. Using cross-country European data, we provide among the first general survey evidence of a strong link between piece rates and workplace injury. Despite controls for workplace hazards, job characteristics and worker effort, piece rates workers suffer a 5 percentage point greater likelihood of injury. This remains despite attempts to control for endogeneity and heterogeneity. As piece rate wage premium estimates rarely control for injury likelihood, this raises the specter that part of that premium reflects a compensating wage differential for risk of injury.     

Testing Multiple Forecasters

We consider a cross‐calibration test of predictions by multiple potential experts in a stochastic environment. This test checks whether each expert is calibrated conditional on the predictions made by other experts. We show that this test is good in the sense that a true expert—one informed of the true distribution of the process—is guaranteed to pass the test no matter what the other potential experts do, and false experts will fail the test on all but a small (category I) set of true distributions. Furthermore, even when there is no true expert present, a test similar to cross‐calibration cannot be simultaneously manipulated by multiple false experts, but at the cost of failing some true experts.     

A short‐form scale to measure sexual discord in dyadic relationships

This paper presents a new short‐form scale for use by clinical workers and researchers in measuring the degree or magnitude of a problem in the sexual component of a dyadic relationship, as seen by the respondent. The scale was designed for use in repeated administrations at periodic intervals in order that therapists might continually monitor and evaluate their clients' response to treatment. Internal consistency and test‐retest reliability were found to be in excess of .90, and the scale has a discriminant validity coefficient of .76.     

Building research capacity for social work practitioners: a regional perspective

This article explores the research experiences, interests and capacity of social work professionals working as frontline workers and managers in human service organizations in regional South Australia. It also draws attention to social work practice issues requiring further investigation as identified by these professionals. The research data for this paper were collected using quantitative and qualitative methods. Quantitative data provided evidence to show the extent of research interests among social work practitioners in the region. Qualitative data added depth to the findings by identifying social work practice issues as described by research participants. The study revealed that few participants had any research experience; however, the majority felt the need to undertake research, expressed interest in research training and a desire to be involved in research projects. These findings have implications for higher education providers in the social work discipline. They draw attention to the importance of better preparing students for research in practice, and also for schools of social work to actively engage in building research capacity and output in regional Australia.

Abbreviations: Frontline social work professionals (FLSWP); The Australian Association of Social Workers (AASW)     

LESSONS FOR RESEARCHERS AND FUNDING AGENCIES FROM HURRICANE KATRINA: A RESEARCH NOTE FROM MISSISSIPPI

We surveyed National Science Foundation (NSF)-funded research in Mississippi to determine the economic extent of research damage and delays due to Hurricane Katrina. While several facilities were physically damaged, we found that the largest effects were time delays and missed opportunities. While psychological factors were not part of the original economic impact study, it became clear that they played an important role. Specifically, the Principal Investigator's (PI's) attitude of “just another delay” was one cultural barrier to fully accounting for the cost of these research delays. We concluded that Principal Investigators, with the assistance of funding agencies, should be better trained to measure time and opportunity costs associated with their research, so future disaster recovery efforts can more fully address those needs.     

Time-on-task, technology and mathematics achievement

Information and communication technologies hold much promise for use in education in developing countries. This study reports on an evaluation conducted on the introduction of computers in the delivery of the mathematics curriculum in one of the provinces of South Africa. Although the request was for an outcome evaluation very early in the implementation of the program, it was tailored in such a way as to fulfill a more formative role. Despite substantial variability in implementation, and in most cases with very weak exposure of the learners to the intervention, sufficient evidence emerged to indicate that this mode of curriculum delivery may be effective. Improvement in mathematics performance was related to a range of variables: some concerned classroom teaching practices, some referred to social differences between the learners, and some to the specific intervention. The strongest of these predictors in the sample was the strength of the intervention: the more time learners spent on using the software to study mathematics, the more improvement they showed from 1 year to the next in their performance in the subject.