External refereed essays

Season Ticket Adoption in Public Transport: The Role of Reliability and Behavioural Inertia

This paper analyses the determinants of peoples’ decision to purchase public transport season tickets. Based on the Deutschlandticket, it focuses on identifying primary customer groups, the role of public transport irregularities such as delays and cancellations, and behavioural inertia of repetitive purchase decisions. It builds on a panel dataset covering survey answers and GPS tracking data from ...

The Value of Care: Brokering Work Conditions and Wages within a Transnational Care System

This article explains how the triadic brokering system in the European Union affects the conditions of work and pay of mobile care workers. Using original survey data gathered from Polish care workers in Germany, the authors found that workers earn less money the more hours they work. Based on qualitative interviews with care workers and representatives of labor market intermediaries, they argue that ...

Heteroskedastic Structural Vector Autoregressions Identified via Long-Run Restrictions

A central assumption for identifying structural shocks in vector autoregressive (VAR) models via heteroskedasticity is the time-invariance of the impact effects of the shocks. It is shown how that assumption can be tested when long-run restrictions based on the cointegration structure of the variables are available for identifying structural shocks. The importance of performing such tests is illustrated ...

Publishing Fine-Grained Standardized Metadata: Lessons Learned from Three Research Data Centers

FAIRness of research data, meaning that data are managed according to the principles of being Findable, Accessible, Interoperable, and Reusable, has become a ubiquitous requirement in research data policies as well as in general guidelines for research data management. Meeting this requirement largely depends on the availability of rich and standardized DDI metadata—based on the Data Documentation ...

Spatial Competition and Pass-through of Fuel Taxes: Evidence from a Quasi-natural Experiment in Germany

This paper analyses determinants of pass-through for Germany’s 2022 temporary fuel discount at its implementation and subsequent termination. Based on a unique dataset of fuel station characteristics and prices, we employ a two-stage Regression Discontinuity in Time (RDiT) methodology to estimate spatial passthrough variation. Our findings indicate that horizontal and vertical market structures exert ...

Ursachen steigender Pflegeversicherungskosten und Wege zur Stabilisierung

Die Folgen des demografischen Wandels werden in der Pflegeversicherung erst in den 2050er Jahren vollumfänglich sichtbar. Dennoch ist der Beitragssatz in den letzten zehn Jahren um mehr als 50 % gestiegen. Der Anstieg hat vor allem politische Gründe. So wurde etwa der Kreis der Leistungsbeziehenden ausgeweitet. Was tun, um den Kostenanstieg zu bremsen? Eine kurzfristige Lösung, die auch zur Systematik ...

Aligning Competition Policy and Industrial Policy in the EU

Trade conflicts, geopolitical tensions, digital disruption, and the climate crisis pose major challenges for the European Union (EU) and its Member States. As called for in the Draghi Report, industrial policy measures can increase competitiveness, strengthen resilience, and facilitate the twin transformation. This article explores ways in which competition policy can be realigned to better accommodate ...

Innovation Dynamics and Technological Maturity in the Fusion Sector: An Assessment of Fusion Projects

Nuclear fusion is envisioned for near-term energy generation deployment, with projected timelines for commercial deployment of fusion expected for the 2030s. Previous research has been limited to either economic or technological maturity assessments of the sector. To address this gap, we design a novel framework that evaluates fusion projects across the most common reactor types and derives the trajectories ...

Rent Control from Ancient Rome to the Paris Commune: A Historical Context

Sector Coupling Reimagined: Synthesizing Fragmented Perspectives Into a Unified Framework

Sector coupling (SC), the integration of energy vectors and end-use sectors, is increasingly central to the net-zero transition but remains conceptually fragmented. This fragmentation causes modeling inconsistencies, hinders cross-study comparison, and undermines energy policy coordination. We address this gap through a structured mapping of existing definitions, categorizing them along three dimensions, ...

Multi-Threshold Time Series Analysis Enables Characterization of Variable Renewable Energy Droughts in Europe

Variable renewable energy droughts, so called Dunkelflaute events, emerge as a challenge for climateneutral energy systems based on variable renewables. Here we characterize European drought events for on- and offshore wind power, solar photovoltaics, and renewable technology portfolios, using 38 historic weather years and an advanced identification method. Their characteristics heavily depend on the ...

Within-Nation Variation in War Exposure and Psychological and Physical Adjustment

What Is the “Right” Geographic Market Definition?

This paper examines the “right” geographic definition of relevant markets by analyzing how excise tax pass-through varies with local competition in the retail gasoline market of a large metropolitan city. Using a natural experiment from three unanticipated and exogenous fuel tax hikes and detailed station-level price data, we show that average pass-through is invariant to the number of nearby competitors ...

Fostering Sustainable and Resilient Coastal Communities Through Combining Nature-Based Solutions and Empowerment Tools: A Review

Nature-based Solutions (NbS) have proven successful to address major coastal environmental challenges. Participatory approaches to NbS planning, design and implementation are increasing, yet community empowerment remains an underexplored aspect of NbS. This paper aims to assess the current state of knowledge on the contribution of community empowerment in NbS approaches to address coastal challenges ...

Beyond Overall Income Inequality: Racial Income Gaps and Health Disparities

In this paper, we combine Census data with death records to examine the relationship between income inequality and race-specific mortality across 5,565 municipalities in Brazil. We find that overall income inequality is strongly associated with Non-White mortality but not with White mortality. To understand this disparity, we decompose the Gini coefficient and find that the racial income gap accounts ...

Public Communication and Collusion: New Screening Tools for Competition Authorities

Competition authorities increasingly rely on economic screening tools to identify markets where firms deviate from competitive norms. Traditional screening methods assume that collusion occurs through secret agreements. However, recent research highlights that firms can use public announcements to coordinate decisions, thereby reducing competition while avoiding detection.We propose a novel approach ...

Unintended Consequences of COVID-19 Public Health and Social Measures in Camps and Camp-Like Settings: A Systematic Review and Conceptual Analysis

Objectives: This study examines unintended consequences (UIC) of public health and social measures (PHSM) in camps and camp-like settings and assesses the pathways through which these UIC arise. Methods: We conducted a systematic review and conceptual analysis of UIC from PHSM aimed at preventing SARS-CoV-2 spread in these settings. PHSM were classified using the WHO taxonomy and the CONSEQUENT framework ...

Heterogeneity in Gender Differences in Self-Reported Political Preferences, Trust, and Well-Being across 39 European Countries

Previous research suggests that women tend to self-report higher life satisfaction and happiness, lower health status and trust, and more left-leaning political preferences than men. We revisit the gender gap in these outcome variables using random-effects meta-analysis, aggregating data across 39 countries surveyed in the European Social Survey (n ≈ 500,000). Measured in Cohen’s d units, women, on ...

The German Artificial Intelligence Experience and Attitude Survey (AIEAS): A Brief Measure for Socio-Economic Panel Studies

Despite the profound impact of artificial intelligence (AI) in diverse contexts, large-scale socio-economic panel studies have rarely addressed the use and evaluation of AI for individual respondents. Therefore, the Artificial Intelligence Experience and Attitude Survey (AIEAS) is introduced to measure awareness, experience, attitude valence, and usage intention regarding AI in the work, healthcare, ...

From Low Emission Zone to Academic Track: Environmental Policy Effects on Educational Achievement in Elementary School

Do long-term improvements in air quality influence children’s educational outcomes? This paper investigates the impact of Low Emission Zones (LEZs), which restrict access to designated areas for emission-intensive vehicles, on the educational achievement of elementary school students in Germany. Using school-level data from North Rhine-Westphalia, Germany’s most populous state, we exploit the staggered ...