Publikationsliste KOPS

The study examines the relationship between sudden- and gradual-onset climate events and migration, hypothesizing that this relationship is mediated by the adaptive capacity of affected individuals. We use survey data from regions of Cambodia, Nicaragua, Peru, Uganda, and Vietnam that were affected by both types of events with representative samples of non-migrant residents and referral samples of migrants. Although some patterns are country-specific, the general findings indicate that less educated and lower-income people are less likely to migrate after exposure to sudden-onset climate events compared to their counterparts with higher levels of education and economic resources. These results caution against sweeping predictions that future climate-related events will be accompanied by widespread migration.

While a large body of research addresses both subject choice and student dropout in higher education, much less is known about switching the initially chosen major. Therefore, we ask why students switch their major in higher education and analyse this for the case of Germany, taking the timing and the degree of such switches (within and across subject groups) into account. Based on the extended rational choice framework, we identify three aspects that might explain switching majors: individual achievement in secondary education, a (mis)match between individual occupational interests and the content of studies and parental and peer judgement regarding the initial subject choice. We test the derived hypotheses by applying logistic regression models to representative data from the German National Educational Panel Study (NEPS), Starting Cohort 5. Our results indicate that the analysed aspects of individual achievement, person-major fit and social expectations affect switching majors, but their influence varies according to the degree and timing of the switch. While high-achieving students are more likely to switch majors, especially across disciplines and at a later stage in their studies, a mismatch in occupational interests mainly affects switching majors across broad subject groups. Finally, disapproval of the initial subject choice by parents and peers matters most for switches during the first two semesters and across academic disciplines.

Background
A previous meta-analysis (Kuiper et al., 2016) has shown that multiple aspects of social relationships are associated with cognitive decline in older adults. Yet, results indicated possible bias in estimations of statistical effects due to the heterogeneity of study design and measurements. We have updated this meta-analysis adding all relevant publications from 2012 to 2020 and performed a cumulative meta-analysis to map the evolution of this growing field of research (+80% of studies from 2012-2020 compared to the period considered in the previous meta-analysis).

Methods
Scopus and Web of Science were searched for longitudinal cohort studies examining structural, functional and combined effects of social relationships. We combined Odds Ratios (OR) with 95% confidence intervals (CI) using random effects meta-analysis and assessed sources of heterogeneity and the likelihood of publication bias. The risk of bias was evaluated with the Quality of Prognosis Studies in Systematic Reviews (QUIPS) tool.

Results
The review was prospectively registered on PROSPERO (ID: CRD42019130667). We identified 34 new articles published in 2012-2020. Poor social relationships were associated with cognitive decline with increasing precision of estimates compared to previously reviewed studies [(for structural, 17 articles, OR: 1.11; 95% CI: 1.08; 1.14) (for functional, 16 articles, OR: 1.12; 95% CI: 1.05; 1.20) (for combined, 5 articles, OR: 1.15; 95% CI: 1.06; 1.24)]. Meta-regression, risk and subgroup analyses showed that the precision of estimations improved in recent studies mostly due to increased sample sizes.

Conclusions
Our cumulative meta-analysis would confirm that multiple aspects of social relationships are associated with cognitive decline. Yet, there is still evidence of publication bias and relevant information on study design is often missing, which could lead to an over-estimation of their statistical effects.

Using administrative German data, we show that large cities allow for a more efficient matching between workers and firms and this has important consequences for geographical inequality. Specifically, the match between high-quality workers and high-quality plants is significantly tighter in large cities relative to small cities. Wages in large cities are higher not only because of the higher worker quality, but also because of a stronger assortative matching. Strong assortative matchig in large cities magnifies wage differences caused by worker sorting, and is a key factor in explaining the growth of geographical wage disparities over the last three decades.

In this study, we merge the literature on homeownership regimes, which focuses to a lesser extent on the consequences of wealth and social inequality, with the literature on wealth and social stratification, which overlooks the importance of homeownership regimes in contributing to those inequalities. Within this framework, we examine to what extent homeownership regimes shape class inequality in homeownership among young adults and the mortgage debt burden that usually accompanies it. We first develop an updated typology of homeownership regimes that incorporates the role of the family via intergenerational wealth transfers (IWT) such as gifts and housing assets. This dimension was theoretically underdeveloped and empirically absent from previous homeownership typologies. Second, we employ this typology to investigate class-based gaps in homeownership and mortgage debt burden within and between homeownership regimes. This is done by pooling data for a total of 20 countries from two sources: the European Union Statistics on Income and Living Conditions (EU-SILC) 2013–2014 (EuroStat) for EU countries, and the Household Expenditure Survey 2012–2013 (CBS) for Israel. Using multivariate modeling, we find that homeownership regimes in which IWT in the form of financial support is common practice increase class inequality in homeownership compared to regimes in which IWT of assets is common practice. Contrary to the literature suggesting that liberal mortgage markets advance inclusion, it appears that in the homeownership regime characterized by the most liberal housing finance system (which includes Northern European countries and the Netherlands), class inequality in mortgaged homeownership is the widest but class inequality in mortgage debt burden is the narrowest. Homeownership regimes characterized by IWT of assets (which include Southern and Central Eastern European countries) reveal the opposite patterns. We discuss the implications of our findings for the literature on homeownership regimes and wealth inequality, with a specific focus on young adults.

Battery electric vehicles generate a significant share of their greenhouse gas emissions during production and later, when in use, through the energy used for charging. A shift in charging behavior could substantially reduce emissions if aligned with the fluctuating availability of renewable energy. Financial incentives and environmental appeals have been discussed as potential means to achieve this. We report evidence from a randomized controlled trial in which cost-free and “green” charging was advertised via email notifications to customers of a charging service provider. Emails invited to charge during midday hours (11:00 to 15:00) of days with high predicted shares of renewable energy. Results show a significant increase in the number of charging processes in the critical time, and in the amount of energy charged (kWh), despite only marginal monetary savings of 5€ on average. A further increase in kWh charged was observed on weekends. Under the assumption that these charging processes replaced regular overnight charging at home, this represents reduction in CO₂ emissions of over 50%.

This review article and special issue introduction argues that studying the relationship between the populist radical right and the welfare state requires bridging literatures that have so far advanced with little mutual engagement: party politics and voting behaviour research on the one hand, and comparative political economy and welfare state research on the other. In this way, the article highlights the advantages of connecting different academic sub-fields in studying radical right politics. First, the literature of comparative political economy on the multi-dimensionality of welfare politics can contribute to a clearer understanding of both the welfare-related causes and consequences of radical right support. Second, the party politics literature on the radical right’s ideology provides theoretical tools to explain the welfare-related consequences of populist radical right parties. The article illustrates the advantages of bridging these literatures through the empirical contributions in this special issue and concludes with avenues of future research.

The European Union, the United Nations, and the United States frequently use economic sanctions. This article introduces the EUSANCT Dataset—which amends, merges, and updates some of the most widely used sanctions databases—to trace the evolution of sanctions after the Cold War. The dataset contains case-level and dyadic information on 326 threatened and imposed sanctions by the EU, the UN, and the US. We show that the usage and overall success of sanctions have not grown from 1989 to 2015 and that while the US is the most active sanctioner, the EU and the UN appear more successful.

In Germany, studies have shown that official coronavirus disease 2019 (COVID-19) vaccination coverage estimated using data collected directly from vaccination centers, hospitals, and physicians is lower than that calculated using surveys of the general population. Public debate has since centered on whether the official statistics are failing to capture the actual vaccination coverage. The authors argue that the topic of one’s COVID-19 vaccination status is sensitive in times of a pandemic and that estimates based on surveys are biased by social desirability. The authors investigate this conjecture using an experimental method called the item count technique, which provides respondents with the opportunity to answer in an anonymous setting. Estimates obtained using the item count technique are compared with those obtained using the conventional method of asking directly. Results show that social desirability bias leads some unvaccinated individuals to claim they are vaccinated. Conventional survey studies thus likely overestimate vaccination coverage because of misreporting by survey respondents.