Transparency and Forecasting: The Impact of Conditioning Assumptions on Forecast Accuracy
Katja Heinisch, Christoph Schult, Carola Stapper
Applied Economic Letters,
forthcoming
Abstract
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.
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Credit Card Entrepreneurs
Ufuk Akcigit, Raman Chhina, Seyit Cilasun, Javier Miranda, Nicolas Serrano-Velarde
IWH Discussion Papers,
No. 5,
2025
Abstract
Utilizing near real-time QuickBooks data from over 1.6 million small businesses and a targeted survey, this paper highlights the critical role credit card financing plays for small business activity. We examine a two year period beginning in January of 2021. A turbulent period during which, credit card usage by small U.S. businesses nearly doubled, interest payments rose by 60%, and delinquencies reached 2.8%. We find, first, monthly credit card payments were up to three times higher than loan payments during this time. Second, we use targeted surveys of these small businesses to establish credit cards as a key financing source in response to firm-level shocks, such as uncertain cash flows and overdue invoices. Third, we establish the importance of credit cards as an important financial transmission mechanism. Following the Federal Reserve’s rate hikes in early 2022, banks cut credit card supply, leading to a 15.75% drop in balances and a 10% decline in revenue growth, as well as a 1.5% decrease in employment growth among U.S. small businesses. These higher rates also rendered interest payments unsustainable for many, contributing to half of the observed increase in delinquencies. Lastly, a simple heterogeneous firm model with a cash-in-hand constraint illustrates the significant macroeconomic impact of credit card financing on small business activity.
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Illusive Compliance and Elusive Risk-shifting after Macroprudential Tightening: Evidence from EU Banking
Michael Koetter, Felix Noth, Fabian Wöbbeking
IWH Discussion Papers,
No. 4,
2025
Abstract
We study whether and how EU banks comply with tighter macroprudential policy (MPP). Observing contractual details for more than one million securitized loans, we document an elusive risk-shifting response by EU banks in reaction to tighter loan-to-value (LTV) restrictions between 2009 and 2022. Our staggered difference-in-differences reveals that banks respond to these MPP measures at the portfolio level by issuing new loans after LTV shocks that are smaller, have shorter maturities, and show a higher collateral valuation while holding constant interest rates. Instead of contracting aggregate lending as intended by tighter MPP, banks increase the number and total volume of newly issued loans. Importantly, new loans finance especially properties in less liquid markets identified by a new European Real Estate Index (EREI), which we interpret as a novel, elusive form of risk-shifting.
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Supply Chain Disruptions and Firm Outcomes
Michael Koetter, Huyen Nguyen, Sochima Uzonwanne
IWH Discussion Papers,
No. 3,
2025
Abstract
This paper examines how firms’ exposure to supply chain disruptions (SCD) affects firm outcomes in the European Union (EU). Exploiting heterogeneous responses to workplace closures imposed by sourcing countries during the pandemic as a shock to SCD, we provide empirical evidence that firms in industries relying more heavily on foreign inputs experience a significant decline in sales compared to other firms. We document that external finance, particularly bank financing, plays a critical role in mitigating the effects of SCD. Furthermore, we highlight the unique importance of bank loans for small and solvent firms. Our findings also indicate that highly diversified firms and those sourcing inputs from less distant partners are less vulnerable to SCD.
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The German Energy Crisis: A TENK-based Fiscal Policy Analysis
Alexandra Gutsch, Christoph Schult
IWH Discussion Papers,
No. 1,
2025
Abstract
We study the aggregate, distributional, and welfare effects of fiscal policy responses to Germany’s energy crisis using a novel Ten-Agents New-Keynesian (TENK) model. The energy crisis, compounded by the COVID-19 pandemic, led to sharp increases in energy prices, inflation, and significant consumption disparities across households. Our model, calibrated to Germany’s income and consumption distribution, evaluates key policy interventions, including untargeted and targeted transfers, a value-added tax cut, energy tax reductions, and an energy cost brake. We find that untargeted transfers had the largest short-term aggregate impact, while targeted transfers were most cost-effective in supporting lower-income households. Other instruments, as the prominent energy cost brake, yielded comparably limited welfare gains. These results highlight the importance of targeted fiscal measures in addressing distributional effects and stabilizing consumption during economic crises.
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Chinesische Massenimporte und Wahlverhalten in Europa: Kann der Aufstieg der politischen Ränder durch Importschocks erklärt werden?
Annika Backes, Steffen Müller
Wirtschaft im Wandel,
No. 4,
2024
Abstract
Wir untersuchen die kurz- und langfristigen Auswirkungen eines starken Anstiegs chinesischer Importe auf Wahlergebnisse in Europa. Populistische sowie links- und rechtsextreme Parteien gewannen erst viele Jahre nach dem Höhepunkt des China-Schocks bedeutenden Zuwachs an Wählerstimmen. Wir zeigen, dass die Auswirkungen von Importschocks überwiegend zugunsten populistischer Parteien ausfallen. In geringerem Maße profitieren in der kurzen Frist zudem linksextreme Parteien, langfristig hingegen rechtsextreme Parteien. Die Effekte auf das Wahlverhalten sind jedoch moderat und wir schlussfolgern, dass Importschocks den Aufstieg der politischen Ränder nur in begrenztem Maße erklären können.
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Forecast Combination and Interpretability Using Random Subspace
Boris Kozyrev
IWH Discussion Papers,
No. 21,
2024
Abstract
This paper investigates forecast aggregation via the random subspace regressions method (RSM) and explores the potential link between RSM and the Shapley value decomposition (SVD) using the US GDP growth rates. This technique combination enables handling high-dimensional data and reveals the relative importance of each individual forecast. First, it is possible to enhance forecasting performance in certain practical instances by randomly selecting smaller subsets of individual forecasts and obtaining a new set of predictions based on a regression-based weighting scheme. The optimal value of selected individual forecasts is also empirically studied. Then, a connection between RSM and SVD is proposed, enabling the examination of each individual forecast’s contribution to the final prediction, even when there is a large number of forecasts. This approach is model-agnostic (can be applied to any set of predictions) and facilitates understanding of how the aggregated prediction is obtained based on individual forecasts, which is crucial for decision-makers.
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05.09.2024 • 24/2024
Moderate economic growth in the world – German economy continues to stagnate
Production in Germany has been stagnating for two years and is roughly the same level as shortly before the outbreak of the pandemic. Investment of firms is particularly weak. An important reason for fewer investments is the sluggish export business. Private households are also holding back on consumption, mainly due to concerns about the longer-term economic outlook. According to the autumn forecast of the Halle Institute for Economic Research (IWH), gross domestic product in Germany is likely to stagnate in 2024 and to increase by 1.0% in 2025 as capacity utilisation normalises. In June, the IWH forecast had still assumed a growth of 0.3% in 2024 and of 1.5% in 2025. In East Germany, gross domestic product will increase by 0.3% this year and by 0.9% in 2025.
Oliver Holtemöller
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Industry Mix, Local Labor Markets, and the Incidence of Trade Shocks
Steffen Müller, Jens Stegmaier, Moises Yi
Journal of Labor Economics,
No. 3,
2024
Abstract
We analyze how skill transferability and the local industry mix affect the adjustment costs of workers hit by a trade shock. Using German administrative data and novel measures of economic distance we construct an index of labor market absorptiveness that captures the degree to which workers from a particular industry are able to reallocate into other jobs. Among manufacturing workers, we find that the earnings loss associated with increased import exposure is much higher for those who live in the least absorptive regions. We conclude that the local industry composition plays an important role in the adjustment processes of workers.
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Import Shocks and Voting Behavior in Europe Revisited
Annika Backes, Steffen Müller
European Journal of Political Economy,
June
2024
Abstract
We provide first evidence for the long-run causal impact that Chinese imports to European regions had on voting outcomes and revisit earlier estimates of the short-run impact for a methodological reason. The fringes of the political spectrum gained ground many years after the China shock plateaued and, unlike an earlier study by Colantone and Stanig (2018b), we do not find any robust evidence for a short-run effect on far-right votes. Instead, far-left and populist parties gained in the short run. We identify persistent long-run effects of import shocks on voting. These effects are biased towards populism and, to a lesser extent, to the far-right.
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