OBJECTIVE — Stress may play a role in the pathogenesis of the metabolic syndrome. However, the scant evidence available is not population-based, restricting the external validity of the findings. Our aim was to test associations between stressful life events, their accumulation, and the metabolic syndrome in a large population-based cohort. We also tested associations between stress and the ind...

Do greater cultural differences between ethnic groups increase the probability of ethnic violence between them? Almost invariably, the questions of interest to social scientists are posed in terms of concepts rooted in ordinary language. In this case, for instance, an empirical inquiry would require a statement of the meaning of “cultural differences,” “ethnic group,” and “ethnic violence.” We ...

We provide a formal definition of the notion of “transportability,” or “external validity,” as a license to transfer causal information from experimental studies to a different population in which only observational studies can be conducted. We introduce a formal representation called “selection diagrams” for expressing differences and commonalities between populations of interest and, using th...

To what use can causal claims established in good policy studies be put? We isolate two reasons inferences from study to target fail. First, policy variables do not produce results on their own; they need helping factors. The distribution of helping factors is likely to be unique or local for each study, so one cannot expect external validity to be all that common. Second, researchers often giv...

Research and applications of behavioral principles have established behavior-based safety initiatives as potentially e€ective solutions to certain occupational health and safety challenges. The present study adds to the existing literature a longitudinal evaluation of an employee-driven behavior-based accident prevention initiative implemented in industrial settings. Up to 5 years of injury dat...

Several empirical studies have been carried out with college students as subjects in the last few years. These studies are often used by researchers as pilot experiments before they are carried out in industrial environments. Reports on these studies usually focus on the results obtained and issues such as their external validity. However, the effects and value of empirical studies with student...

Background Many patients decline participation in randomised trials due to treatment preferences. It is not known whether it is possible to combine evidence from those choosing treatment and those randomised in RCTs with parallel non-randomised preference groups without compromising external validity. This study explored whether people who chose their treatment within an RCT in which recruiters...

Over the last decades, there has been a steady increase in the use of experimental methods in economics. We discuss the advantages of experiments for labour economics in this paper. Control is the most important asset behind running experiments; no other empirical method allows a similarly tight control as do experiments. Moreover, experiments produce replicable evidence and permit the implemen...

The present study presents preliminary evidence regarding the reliability and validity of the Multidimensional Inventory of Black Identity (MIBI). The MIBI consists of 7 subscales representing 3 stable dimensions of African American racial identity (Centrality, Ideology, and Regard). Responses to the MIBI were collected from 474 African American college students from a predominantly African Ame...

Most methodological discussion in experimental economics has been pursued by justifying the use of experiments as theory testing vehicles. More recently it has also been argued that the external validity of experiments requires the use of nonexperimental field evidence. Therefore, it is argued, experiments are intermediaries between theories and field evidence. In this paper it is proposed that...