Improved Transferability of Data‐Driven Damage Models Through Sample Selection Bias Correction

Damage models for natural hazards are used for decision making on reducing and transferring risk. The damage estimates from these models depend on many variables and their complex sometimes nonlinear relationships with the damage. In recent years, data‐driven modeling techniques have been used to capture those relationships. The available data to build such models are often limited. Therefore, in practice it is usually necessary to transfer models to a different context. In this article, we show that this implies the samples used to build the model are often not fully representative for the situation where they need to be applied on, which leads to a “sample selection bias.” In this article, we enhance data‐driven damage models by applying methods, not previously applied to damage modeling, to correct for this bias before the machine learning (ML) models are trained. We demonstrate this with case studies on flooding in Europe, and typhoon wind damage in the Philippines. Two sample selection bias correction methods from the ML literature are applied and one of these methods is also adjusted to our problem. These three methods are combined with stochastic generation of synthetic damage data. We demonstrate that for both case studies, the sample selection bias correction techniques reduce model errors, especially for the mean bias error this reduction can be larger than 30%. The novel combination with stochastic data generation seems to enhance these techniques. This shows that sample selection bias correction methods are beneficial for damage model transfer.     

Radical Distrust: Are Economic Policy Attitudes Tempered by Social Trust?

Social Indicators Research - Debates about the appropriate role of markets and governments are often shaped by sharply contrasting opinions. Based on individual data from the World Values Survey...     

A vector of quarters representation for bivariate time series

In this paper it is shown that several models for a bivariate nonstationary quarterly time series are nested in a vector autoregression with cointegration restrictions for the eight annual series of quarterly observations. Or, the Granger Representation Theorem is extended to incorporate, e.g., seasonal and periodic cointegration.     

Book reviews

Statistical Papers -     

Detecting seasonal unit roots in a structural time series model

In this paper, we propose to detect seasonal unit roots within the context of a structural time series model. Such a model is often found to be useful in practice. Using Monte Carlo simulations, we show that our method works well. We illustrate our approach for several quarterly macroeconomic time series variables.     

Hierarchy or co-operation: labour-management relations in church institutions

Aspects of industrial relations and internal co-ordination have been a major topic of empirical research in the German business enterprise sector. In contrast, there are practically no empirical investigations into labour-management relations in third sector institutions. The largest share of this sector in Germany is represented by the two Christian churches with presently about 900,000 employees. According to the notion of church officials, labour-management relations in these institutions are characterised by a specific normative concept which emphasises a trustful co-operation of all employees in the mission of the church. The major concern of our research project focused on the question whether the specific conditions of employment within church institutions favour more hierarchical or more co-operative forms of co-ordination and how employees and employee representatives perceive the ideal of the community of service (Dienstgemeinschaftsgedanke). The results of our research lead to the conclusion that church labour-management relations are characterised by a remarkable contrast between the participative or co-operative notion of the ideal of the community of service and present forms of hierarchical co-ordination inside church institutions.This article gives a selected overview of Beyer and Nutzinger (1991). The research was supported by the Hans-Böckler-Stiftung (Düsseldorf) and the University of Kassel.     

Compliance Versus Risk in Assessing Occupational Exposures

Assessments of occupational exposures to chemicals are generally based upon the practice of compliance testing in which the probability of compliance is related to the exceedance [γ, the likelihood that any measurement would exceed an occupational exposure limit (OEL)] and the number of measurements obtained. On the other hand, workers’ chronic health risks generally depend upon cumulative lifetime exposures which are not directly related to the probability of compliance. In this paper we define the probability of “overexposure” (θ) as the likelihood that individual risk (a function of cumulative exposure) exceeds the risk inherent in the OEL (a function of the OEL and duration of exposure). We regard θ as a relevant measure of individual risk for chemicals, such as carcinogens, which produce chronic effects after long-term exposures but not necessarily for acutely-toxic substances which can produce effects relatively quickly. We apply a random-effects model to data from 179 groups of workers, exposed to a variety of chemical agents, and obtain parameter estimates for the group mean exposure and the within- and between-worker components of variance. These estimates are then combined with OELs to generate estimates of γ and θ. We show that compliance testing can significantly underestimate the health risk when sample sizes are small. That is, there can be large probabilities of compliance with typical sample sizes, despite the fact that large proportions of the working population have individual risks greater than the risk inherent in the OEL. We demonstrate further that, because the relationship between θ and γ depends upon the within- and between-worker components of variance, it cannot be assumed a priori that exceedance is a conservative surrogate for overexposure. Thus, we conclude that assessment practices which focus upon either compliance or exceedance are problematic and recommend that employers evaluate exposures relative to the probabilities of overexposure.     

Appropriating Care and Hijacking Desire: Thought and Praxis in Human Services Under 21st Century Capitalism

In this article, we trace the rise of neoliberalism and its impacts on the historical role of human services within the academy and the community. We ask whether we can re-think and re-envision a 21st century academy rooted in the material actualities of daily living and connected in very real ways to the struggles of those Human Services was designed to serve. Finally, we propose that Human Services could have a significant role to play in developing new modes of value that could lead to new modes of thought and new avenues of praxis.