Treatment‐as‐usual in effectiveness studies: What is it and does it matter?

Andrée Löfholm C, Brännström L, Olsson M, Hansson K. Treatment‐as‐usual in effectiveness studies: What is it and does it matter? A hallmark of an evidence‐based practice (EBP) is the systematic appraisal of research related to the effectiveness of interventions. This study addressed the issue of interpreting results from effectiveness studies that use treatment‐as‐usual (TAU) as a comparator. Using randomised controlled studies that evaluate the effectiveness of multisystemic therapy as an illustrative example, we show that TAU includes a wide variety of treatment alternatives. Estimated treatment effects on recidivism suggest that TAU seems to contain a greater variation in underlying risk than experimental conditions, supporting the hypothesis that the content of TAU could affect outcomes. Implications for the realisation of an EBP are discussed.     

How Job Characteristics Affect International Migration: The Role of Informality in Mexico

Despite the importance given to employment opportunities as a primary motive for migration, previous studies have paid insufficient attention to the kinds of jobs that are more likely to retain workers in their countries of origin. We use information from a panel survey of Mexican adults to examine how job characteristics affect the risk of international migration. The sampling strategy and overall size of the survey allow us to analyze the effect of employment characteristics on migration from urban areas, which have much greater labor market diversity, and to separate our analysis by gender. We also distinguish migrants according to whether they migrate for work or for other reasons. We find informality to be a significant predictor of international migration. Even after controlling for individual factors including workers’ wages, as well as various household- and community-level predictors, we find that workers employed in the informal sector have significantly higher odds of migrating than their counterparts in the formal sector. The pervasive nature of informality in many developing countries from which a high proportion of international migrants originate may therefore create a constant supply of workers who are predisposed to migrate. Our findings thus have important implications for a proper understanding of the effects of economic development on migration.     

NISO Webinar: The Future of Integrated Library Systems: Part 1: RDA & Cataloging

Abstract

This column's offerings cover late spring through summer to fall of 2011: NISO Webinar: The Future of Integrated Library Systems: Part 1: RDA & Cataloging (May 11); American Library Association Annual Conference (June 23–28); Association of College and Research Libraries New England Serials and Electronic Resources Interest Group Summer Program: Current Trends in E-Journals (August 18); Kentucky Library Association/Kentucky School Media Association Joint Conference (September 28–October 1); American Society for Information Science and Technology Annual Meeting (October 9–12); Great Lakes E-Summit Conference (October 10–11); and Potomac Technical Processing Librarians Annual Meeting (October 21).     

Incidence of Social Accountability in Local Governance: The Case of the Network for Fair,Democratic and Sustainable Cities and Territories in Latin America

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - In Latin America, the emergence of a series of civil society initiatives aimed at citizen engagement for social...     

Application of Correspondence Analysis in the Assessment of Mine Tailings Dam Breakage Risk in the Mediterranean Region

A new statistical approach for preliminary risk evaluation of breakage in tailings dam is presented and illustrated by a case study regarding the Mediterranean region. The objective of the proposed method is to establish an empirical scale of risk, from which guidelines for prioritizing the collection of further specific information can be derived. The method relies on a historical database containing, in essence, two sets of qualitative data: the first set concerns the variables that are observable before the disaster (e.g., type and size of the dam, its location, and state of activity), and the second refers to the consequences of the disaster (e.g., failure type, sludge characteristics, fatalities categorization, and downstream range of damage). Based on a modified form of correspondence analysis, where the second set of attributes are projected as "supplementary variables" onto the axes provided by the eigenvalue decomposition of the matrix referring to the first set, a "qualitative regression" is performed, relating the variables to be predicted (contained in the second set) with the "predictors" (the observable variables). On the grounds of the previously derived relationship, the risk of breakage in a new case can be evaluated, given observable variables. The method was applied in a case study regarding a set of 13 test sites where the ranking of risk obtained was validated by expert knowledge. Once validated, the procedure was included in the final output of the e-EcoRisk UE project (A Regional Enterprise Network Decision-Support System for Environmental Risk and Disaster Management of Large-Scale Industrial Spills), allowing for a dynamic historical database updating and providing a prompt rough risk evaluation for a new case. The aim of this section of the global project is to provide a quantified context where failure cases occurred in the past for supporting analogue reasoning in preventing similar situations.     

Pooling in Dynamic Panel-Data Models: An Application to Forecasting GDP Growth Rates

In this article, we analyze issues of pooling models for a given set of N individual units observed over T periods of time. When the parameters of the models are different but exhibit some similarity, pooling may lead to a reduction of the mean squared error of the estimates and forecasts. We investigate theoretically and through simulations the conditions that lead to improved performance of forecasts based on pooled estimates. We show that the superiority of pooled forecasts in small samples can deteriorate as the sample size grows. Empirical results for postwar international real gross domestic product growth rates of 18 Organization for Economic Cooperation and Development countries using a model put forward by Garcia-Ferrer, Highfield, Palm, and Zellner and Hong, among others illustrate these findings. When allowing for contemporaneous residual correlation across countries, pooling restrictions and criteria have to be rejected when formally tested, but generalized least squares (GLS)-based pooled forecasts are found to outperform GLS-based individual and ordinary least squares-based pooled and individual forecasts.     

A Model of Minimal Probabilistic Belief Revision

In the literature there are at least two models for probabilistic belief revision: Bayesian updating and imaging [Lewis, D. K. (1973), Counterfactuals, Blackwell, Oxford; Gärdenfors, P. (1988), Knowledge in flux: modeling the dynamics of epistemic states, MIT Press, Cambridge, MA]. In this paper we focus on imaging rules that can be described by the following procedure: (1) Identify every state with some real valued vector of characteristics, and accordingly identify every probabilistic belief with an expected vector of characteristics; (2) For every initial belief and every piece of information, choose the revised belief which is compatible with this information and for which the expected vector of characteristics has minimal Euclidean distance to the expected vector of characteristics of the initial belief. This class of rules thus satisfies an intuitive notion of minimal belief revision. The main result in this paper is to provide an axiomatic characterization of this class of imaging rules.