Publications
Published Papers
Retirement and cognitive abilities: Evidence from the German early retirement age reform for women
Henrik Bergschneider, Robin Kottmann, Hendrik Schmitz, Matthias Westphal. “Retirement and cognitive abilities: Evidence from the German early retirement age reform for women.” Journal of Health Economics, Vol. 108, 103161 (2026).
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Abstract
We study the effects of retirement on cognitive functioning among women aged 63 to 67 by exploiting a German retirement reform that raised the early retirement age for women born after 1951 by three years, from 60 to 63. Our indicators of cognitive functioning are objective cognitive test scores (word recall, semantic fluency, and the Stroop test) from a large biomedical dataset, as well as the diagnosis of cognitive disorders from administrative health insurance claims. We find reductions of around 13% of a standard deviation per year in retirement for measures of fluid intelligence, whereas crystallized intelligence remains unaffected. These estimates reflect the reform-induced shift in retirement duration for compliers around the eligibility cutoff. In contrast, additional years in retirement do not affect diagnosis of cognitive disorder and decrease diagnoses of dementia-related risk factors such as hypertension, depression, and sleep problems. The improvement in health outcomes suggests that cognitive decline is not driven by health deterioration but might possibly be due to reduced cognitive engagement after leaving work.Working Papers
Low Depression Zones? The Effect of Driving Restrictions on Air Pollution and Mental Health
Johannes Brehm, Henri Gruhl, Robin Kottmann, Laura Schmitz. “Low Depression Zones? The Effect of Driving Restrictions on Air Pollution and Mental Health.” Ruhr Economic Papers 1093 (2024)
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Abstract
Does exposure to air pollution impact mental health? This paper uses administrative health insurance data to estimate the medium-term cumulative effects of air pollution exposure on mental health outcomes. For identification, we exploit the staggered introduction of Low Emission Zones (LEZs) across German cities, which restrict access for emission-intensive vehicles. We find that LEZs reduce various air pollutants and improve the population's mental health measured by depression and anxiety diagnoses, prescriptions, and specialist visits. The health benefits emerge gradually, with younger individuals benefiting the most. Our findings suggest substantial mental health co-benefits and avoided health costs from improved air quality.Work in Progress
Can Hospitals Protect Patients from Extreme Heat? Evidence from Hospital-Acquired Dehydration.
Henri Gruhl, Robin Kottmann. Submitted. Draft on request.
Abstract
Is the healthcare system equipped to protect patients from extreme heat? We study this question in the hospital sector, using hospital-acquired dehydration as a marker of heat-related health deterioration. Linking daily temperature data to administrative health insurance records covering 34.1 million German hospital admissions, we estimate the effect of inpatient heat exposure on dehydration diagnoses among patients without dehydration at admission. We find that extreme heat substantially increases the risk of hospital-acquired dehydration. Relative to hospital stays with temperatures between 15 and 20°C, stays with temperatures above 30°C raise the probability of dehydration by 0.67 percentage points, an 18 percent increase relative to the baseline incidence. These effects are concentrated among older patients and those with dementia, highlighting greater vulnerability among individuals requiring intensive monitoring. Our findings demonstrate that climate change threatens health systems not only by increasing external demand for care, but also by exposing internal institutional limitations, underscoring the urgent need for hospital adaptation to prevent avoidable in-hospital health deterioration.Ambient Temperature and the Risk of Hospital-Acquired Infections.
Robin Kottmann. Draft on request.
Abstract
This study estimates how short-run exposure to extreme temperatures affects hospital-acquired infections (HAIs). Using German administrative health data (2005-2023) linked to local weather, I exploit quasi-random daily temperature variation during the first three days of admission. I find that extreme heat significantly increases HAI risk: each day ≥30°C raises infection probability by 0.06 percentage points (1.43 percent), while extreme cold reduces it. These effects are concentrated among vulnerable patients, high-risk procedures, smaller hospitals, and historically cooler regions. These findings highlight a critical clinical channel through which climate change impacts healthcare systems.Retirement Duration Effects on Health
Henrik Bergschneider, Robin Kottmann, Hendrik Schmitz, Matthias Westphal