This study investigates the impact of inaccurate assumptions on economic forecast precision. We construct a new dataset comprising an unbalanced panel of annual German GDP forecasts from various institutions, taking into account their underlying assumptions. We explicitly control for different forecast horizons to reflect the information available at the time of release. Our analysis reveals that approximately 75% of the variation in squared forecast errors can be attributed to the variation in squared errors of the initial assumptions. This finding emphasizes the importance of accurate assumptions in economic forecasting and suggests that forecasters should transparently disclose their assumptions to enhance the usefulness of their forecasts in shaping effective policy recommendations.

In this paper, we use granular trading data from Taiwan between 2012 and 2016 to examine how local social capital influences retail investor behavior during corporate social irresponsibility (CSIR) events. Therefore, we are responding to longstanding calls in the international finance literature to explore investor behavior in non-US markets with distinct institutional and cultural characteristics. We find that investors residing in cities with higher social capital are less likely to purchase underpriced stocks following the announcements of negative events despite the potential for positive abnormal returns. This norm-driven restraint reflects a form of socially responsible investing motivated by community-based values rather than economic rationality. By documenting this behavior in an East Asian market, we extend the external validity of social norm theories developed in Western settings and contribute to a more nuanced understanding of how localized social preferences can influence asset pricing and capital allocation in a global context.

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.

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.

Schriftliche Anhörung des Finanzausschusses des Landtags Mecklenburg-Vorpommern

Welche Wachstumsimpulse können zusätzliche, kreditfinanzierte Finanzmittel für Infrastruktur, Klimaneutralität und Verteidigung in Mecklenburg-Vorpommern setzen? Im Rahmen einer schriftlichen Anhörung des Finanzausschusses des Landtages Mecklenburg-Vorpommern beantwortet das IWH Fragen zur Verwendung der Finanzmittel und zur möglichen Wirkung von zusätzlichen Investitionen auf das Produktionspotenzial und das Wirtschaftswachstum in Mecklenburg-Vorpommern. Angesichts der demographischen Entwicklung ist die Arbeitsproduktivität der Schlüssel zur Verbesserung der Wachstumsaussichten des Landes.

We investigate whether a change in political leadership affects health outcomes. To do so, we exploit turnover elections that move partisan individuals into and out of alignment with the party of the President. We document that the lack of political alignment has a negative, immediate, and long-lasting effect on health. We do not find any evidence that our results can be explained by other confounding trends or by changes in economic outcomes or other economic policies. Further results suggest that political sentiments and social isolation are important potential mechanisms in this setting and that lack of political representation affects the mental health of individuals.

Die Projektgruppe Gemeinschaftsdiagnose prognostiziert für das Jahr 2025 einen leichten Zuwachs des Bruttoinlandsprodukts in Deutschland um 0,2 %. Im weiteren Prognosezeitraum stimuliert die expansive Finanzpolitik die Konjunktur. Die Institute prognostizieren für die kommenden beiden Jahre Expansionsraten von 1,3 % und 1,4 %. Strukturelle Probleme wie abnehmende Wettbewerbsfähigkeit und der demografische Wandel bleiben bestehen. Um Wachstumsperspektiven für die deutsche Wirtschaft zu schaffen, bedarf es einer umfangreichen Reformpolitik. Zur Orientierung präsentieren die Institute einen Zwölf-Punkte-Kompass für den Herbst der Reformen.

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.