Discrete–Time Approximations of the Holmström–Milgrom Brownian–Motion Model of Intertemporal Incentive Provision

This paper studies the relation between discrete–time and continuous–time principal–agent models. We derive the continuous–time model as a limit of discrete–time models with ever shorter periods and show that optimal incentive schemes in the discrete–time models approximate the optimal incentive scheme in the continuous model, which is linear in accounts. Under the additional assumption that the principal observes only cumulative total profits at the end and the agent can destroy profits unnoticed, an incentive scheme that is linear in total profits is shown to be approximately optimal in the discrete–time model when the length of the period is small.     

Circular and Repeat Migration: Counts of Exits and Years Away from the Host Country

The importance of repeat and circular migration starts receiving rising recognition. The paper studies this behavior by analyzing the number of exits and the total number of years away from the host country using count data models and panel data from the German guestworker experience. Beyond the myth, more than 60% of migrants in the sample from the guestworker countries living in Germany are indeed repeat or circular migrants. Migrants from European Union member countries, those not owning a dwelling in Germany, the younger and the older (excluding the middle-aged), are significantly more likely to engage in repeat migration and to stay out for longer. Males and those migrants with German passports exit more frequently, while those with higher education exit less; there are no differences with time spent out. Migrants with family in the home country remain out longer, and those closely attached to the labor market remain less; they are not leaving the country more frequently.     

Growth and Poverty Reduction in Uganda, 1999–2000: Panel Data Evidence

To explore factors underlying growth and poverty reduction in Africa while overcoming some of the limitations of cross‐country analysis, this article uses micro‐level survey and panel‐data evidence from Uganda spanning 1992–2000. The high elasticity of both income growth and poverty reduction with respect to agricultural output (coffee) prices confirms the benefits from Uganda's decisive liberalisation of output markets. It also suggests the importance of product diversification to protect the poor against price shocks and the potential of cotton‐market improvements in tackling persistent poverty in the North. The importance of improving access to basic education and health care emerges more clearly than in cross‐country analysis, but benefits depend on complementary investments in electricity and other infrastructure, and reductions in civil strife.     

Police Accounts of Body-Worn Camera Footage In News Media

People offer accounts in response to actions that are subjected to valuative inquiry. Recordings of police actions captured on body-worn camera (BWC) video can become subject to valuative inquiry when footage is publicly released. This footage may possibly undermine police legitimacy. Managing legitimacy is a basic rationale for why police provide accounts in response to their conduct. Proponents of BWCs assert that the devices enhance legitimacy and, while police have long used accounts to justify their conduct, less is known about how body cameras affect police accountability in practice. Drawing from Scott and Lyman's accounts theory framework, this qualitative, exploratory study examines official police accounts as both outcomes of police accountability in practice and as provided in the context of news media coverage of publicly released body-worn camera footage. This allows us to ask the following questions: What types of accounts have police officials provided in news media reports in the context of publicly released BWC footage? And, more generally, what insight might an analysis of police accounts provide about accountability in relation to the implementation of BWCs? A key finding reveals that the timing of police accounts varied quite considerably, and that accounts were usually not static. The findings provide some general insight into what kinds of actions captured on body camera recordings constitute acceptable use of force by officers, even in situations when police actions resulted in death. This study also provides a small empirical window into when and how police officials provide accounts in response to publicly released body camera footage.     

Standardisierungspotentiale lebenszyklusbasierter Modelle des strategischen Kostenmanagements

Tremendous increases in indirect costs can be found in many industries. Consequently, life cycle cost analysis models are getting more important in strategic cost management. However, existing models differ significantly from each other as they have been developed mainly for specific applications. In order to enable a common use of those models, a standardization of these models is required. We examine the potentials of standardizing models for life cycle cost analysis. In a first step, requirements regarding a standard model are derived from literature. As a second step, existing approaches found in literature are compared to the afore derived demands and it is analyzed to what extent they match the standardization requirements. Based on this comparison, we identify and discuss avenues for further research.     

LINGUISTIC DIVERSITY AND REDISTRIBUTION

This paper investigates the effect of linguistic diversity on redistribution in a broad cross‐section of countries. We use the notion of “linguistic distances” and show that the commonly used fractionalization index, which ignores linguistic distances, yields insignificant results. However, once distances between languages are accounted for, linguistic diversity has both a statistically and economically significant effect on redistribution. With an average level of redistribution of 9.5% of GDP in our data set, an increase byone standard deviation in the degree of diversity lowers redistribution by approximately one percentage point. We also demonstrate that other measures, such as polarization and peripheral heterogeneity, provide similar results when linguistic distances are incorporated. (JEL: D6, D74, H5, Z10)     

A Method for Computing the Fraction of Attributable Risk Related to Climate Damages

The recent decision of the U.S. Supreme Court on the regulation of CO₂ emissions from new motor vehicles^{( 1 )} shows the need for a robust methodology to evaluate the fraction of attributable risk from such emissions. The methodology must enable decisionmakers to reach practically relevant conclusions on the basis of expert assessments the decisionmakers see as an expression of research in progress, rather than as knowledge consolidated beyond any reasonable doubt.^{( 2,3,4 )} This article presents such a methodology and demonstrates its use for the Alpine heat wave of 2003. In a Bayesian setting, different expert assessments on temperature trends and volatility can be formalized as probability distributions, with initial weights (priors) attached to them. By Bayesian learning, these weights can be adjusted in the light of data. The fraction of heat wave risk attributable to anthropogenic climate change can then be computed from the posterior distribution. We show that very different priors consistently lead to the result that anthropogenic climate change has contributed more than 90% to the probability of the Alpine summer heat wave in 2003. The present method can be extended to a wide range of applications where conclusions must be drawn from divergent assessments under uncertainty.     

Role of National Divorce Rates in Moderating the Association Between Marriage Duration and Body Mass Index

The aim of this study was to investigate the moderating effects of the national divorce rate on the association between body weight and marriage duration. Previous studies argued that a high divorce rate at country level reduces the body weight of married people because of an increased risk of a return to the marriage market. To examine the association in question, this study used retrospective data from 14,083 middle-aged individuals in Europe. For women the divorce rate, the percentage change, and the trend of change did not moderate the positive association between body mass index and marriage duration. In contrast, for men a high divorce rate and a steady decline over time positively moderated the relation between body mass index and marriage duration.     

Being Known in Undergraduate Social Work Education: The Role of Instructors in Fostering Student Engagement and Motivation

Most undergraduate students pursue a social work major because of their desire to help others. Students tend to be more interested in doing than in understanding the research and knowledge of the profession and the complexities of social work practice. Instructors are often faced with the challenge of enhancing student motivation to learn challenging course material. This study explored student perceptions of instructor influences on their motivation and engagement in learning. Through online surveys, students described their experiences of being known and how those experiences affected their participation in practice, research, and human behavior in the social environment courses. Results showed that instructor caring (providing recognition, expressing relational qualities, and responding to students) positively influences student motivation and affective learning by increasing comfort, willingness to ask questions, take risks, and overall participation. Conversely, of those who reported mixed experiences or who felt unknown, most reported a negative impact on their motivation and participation. These findings suggest that social work faculty can influence student motivation and engagement with essential social work curriculum by expressing care and helping students feel known in the classroom.