The Price of Beauty: Biodiversity Effects on Residential Housing Markets
Michael Koetter, Birte Winter, Fabian Woebbeking
IWH Discussion Papers,
No. 21,
2025
Abstract
We study how and why local biodiversity affects residential property values. Leveraging remotely sensed greenness indicators and a novel dataset of granular property listings, we examine how changes in vegetation load on real estate prices. Hikes in greenness are associated with higher listing prices, fewer properties listed, and reduced liquidity in housing markets. These results suggest that price hikes in housing markets are driven by supply-side constraints instead of a “greenium” that buyers might be willing to pay due to innate preferences. Exogenous zoning shocks to foster biodiversity corroborate the presence of supply side constraints as price drivers in residential housing markets. Our findings emphasize the need to calibrate biodiversity and (social) housing policy objectives more explicitly.
Read article
Cross-border Transmission of Climate Policies Through Global Production Networks
Marius Fourné
IWH Discussion Papers,
No. 19,
2025
Abstract
Climate policies do not operate in isolation but propagate through global production networks, affecting industries beyond national borders. This paper combines international input-output data with a granular instrumental variable approach to capture how foreign regulations transmit through upstream and downstream linkages. Distinguishing between market-based policies, non-market regulations, and technology support, the analysis shows that foreign climate policies can enhance domestic productivity, with effects shaped by industry characteristics and operating through technological adjustment along supply chains. The results underscore the importance of accounting for international spillovers when evaluating the economic impact of environmental regulation.
Read article
Road to Net Zero: Carbon Policy and Redistributional Dynamics in the Green Transition
Alessandro Sardone
IWH Discussion Papers,
No. 16,
2025
Abstract
This paper examines the macroeconomic and distributional effects of the European Union’s transition to Net Zero emissions through a gradually increasing carbon tax. I develop a New Keynesian Environmental DSGE model with two household types and distinct energy and non-energy sectors. Five alternative uses of carbon tax revenues are considered: equal transfers to households, targeted transfers to Hand-to-Mouth households, subsidies to green energy firms, and reductions in labor and capital income taxes. In the absence of technological progress, the carbon tax policy induces a persistent increase in energy prices and a reduction in GDP, investment, and consumption. Headline inflation falls below zero in the medium run, reflecting weaker aggregate demand. Distributional outcomes vary significantly depending on the implemented revenue recycling scheme: targeted transfers are the most progressive but entail larger macroeconomic costs, while subsidies and tax cuts mitigate output and investment losses but are less effective in narrowing the consumption gap. A limited foresight scenario, in which agents learn about policy targets sequentially, generates more volatile adjustment paths and temporary inflationary spikes around announcements, but long-run outcomes remain close to the baseline.
Read article
Employment Effects of Investment Grants and Firm Heterogeneity
Eva Dettmann, Antje Weyh, Mirko Titze
Regional Studies,
Vol. 59 (1),
2025
Abstract
This study estimates the firm-level employment effects of investment grants in Germany. In addition to the average treatment effect on the treated, we examine discrimination in the funding rules as a potential source of effect heterogeneity. We combine a staggered difference-in-differences approach with a matching procedure at the cohort level. The findings reveal a positive effect of investment grants on employment development. The subsample analyses yield strong evidence for heterogeneous effects based on firm characteristics and the economic environment. They highlight the responsibility of the local funding authorities to clarify ex ante which goals of a funding programme are most important in their regions.
Read article
Declining Free Lunch: State Capacity and Foregone Public Spending
Sarah Fritz, Lorenzo Incoronato, Catherine van der List
RFBerlin Discussion Paper,
No. 67,
2025
Abstract
This paper documents substantial fiscal waste in the context of one the world’s largest regional development programs – the EU Cohesion Policy. We study Italy, and find that 20% of funding commitments are never paid out and funneled into unfinished or never-started projects. In our setting, this happens for reasons unrelated to fiscal constraints – municipalities appear to simply leave money on the table. Foregone spending is more prevalent in Southern regions, but there is also stark variation across municipalities within regions. We show that such under-utilization of available funds is strongly associated with limited administrative capacity of local governments.
Read article
Real Estate Transaction Taxes and Credit Supply
Michael Koetter, Philipp Marek, Antonios Mavropoulos
Journal of Financial Stability,
Vol. 80 (September),
2025
Abstract
We exploit staggered real estate transaction tax (RETT) hikes across German states to identify the effect of house price changes on mortgage credit supply. Based on approximately 33 million real estate online listings, we construct a quarterly hedonic house price index (HPI) between 2008:q1 and 2017:q4, which we instrument with state-specific RETT changes to isolate the effect on mortgage credit supply by all local German banks. First, a RETT hike by one percentage point reduces HPI by 1.2%. This effect is driven by listings in rural regions. Second, a 1% contraction of HPI induced by an increase in the RETT leads to a 1.4% decline in mortgage lending. This transmission of fiscal policy to mortgage credit supply is effective across almost the entire bank capitalization distribution.
Read article
Media Response
Media Response April 2026 Oliver Holtemöller: Tanken, Essen, Leben - alles teurer! Wie bändigt man die Inflation? in: MDR Fernsehen "Fakt ist!", 22.04.2026 Reint Gropp:…
See page
10th Vintage
The CompNet 10th Vintage Dataset 10th Vintage dataset is now available! The CompNet dataset provides a comprehensive set of micro-aggregated indicators, specifically designed to…
See page
Alumni
Alumni IWH provides guidance and support in job placement after graduation, including letters of recommendation and career advice. Graduates have found placements in academia…
See page
Research Clusters
Three Research Clusters Each IWH research group is assigned to a topic-oriented research cluster. The clusters are not separate organisational units, but rather bundle the…
See page