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
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 arising in 2022 using a novel ten-agent new Keynesian (TENK) model. The crisis, compounded by the COVID-19 pandemic, led to sharp price increases and significant consumption disparities. Our model, calibrated to Germany’s income and consumption distribution, evaluates key policy interventions. We find that untargeted transfers had the largest short-term aggregate impact, while targeted transfers for lower-income households were most cost-effective. Other instruments yielded comparably limited welfare gains. The results highlight how targeted fiscal measures can address distributional effects and stabilize consumption during crises.
Read article
Media Response
Media Response November 2025 Reint Gropp: Expertendialog: Wege zur Stärkung des Wirtschaftswachstums in Deutschland in: Youtube, 12.11.2025 Steffen Müller: Wir erwarten das…
See page
Alumni
IWH Alumni The IWH maintains contact with its former employees worldwide. We involve our alumni in our work and keep them informed, for example, with a newsletter. We also plan…
See page
Is Risk the Fuel of the Business Cycle? Financial Frictions and Oil Market Disturbances
Christoph Schult
IWH Discussion Papers,
No. 4,
2024
Abstract
I estimate a dynamic stochastic general equilibrium (DSGE) model for the United States that incorporates oil market shocks and risk shocks working through credit market frictions. The findings of this analysis indicate that risk shocks play a crucial role during the Great Recession and the Dot-Com bubble but not during other economic downturns. Credit market frictions do not amplify persistent oil market shocks. This result holds as long as entry and exit rates of entrepreneurs are independent of the business cycle.
Read article
Macroeconomic Effects from Sovereign Risk vs. Knightian Uncertainty
Ruben Staffa
IWH Discussion Papers,
No. 27,
2023
Abstract
This paper compares macroeconomic effects of Knightian uncertainty and risk using policy shocks for the case of Italy. Drawing on the ambiguity literature, I use changes in the bid-ask spread and mid-price of government bonds as distinct measures for uncertainty and risk. The identification exploits the quasi-pessimistic behavior under ambiguity-aversion and the dealer market structure of government bond markets, where dealers must quote both sides of the market. If uncertainty increases, ambiguity-averse dealers will quasi-pessimistically quote higher ask and lower bid prices – increasing the bid-ask spread. In contrast, a pure change in risk shifts the risk-compensating discount factor which is well approximated by the change in bond mid-prices. I evaluate economic effects of the two measures within an instrumental variable local projection framework. The main findings are threefold. First, the resulting shock time series for uncertainty and risk are uncorrelated with each other at the intraday level, however, upon aggregation to monthly level the measures become correlated. Second, uncertainty is an important driver of economic aggregates. Third, macroeconomic effects of risk and uncertainty are similar, except for the response of prices. While sovereign risk raises inflation, uncertainty suppresses price growth – a result which is in line with increased price rigidity under ambiguity.
Read article
Fiscal Policy under the Eyes of Wary Bondholders
Ruben Staffa, Gregor von Schweinitz
IWH Discussion Papers,
No. 26,
2023
Abstract
This paper studies the interaction between fiscal policy and bondholders against the backdrop of high sovereign debt levels. For our analysis, we investigate the case of Italy, a country that has dealt with high public debt levels for a long time, using a Bayesian structural VAR model. We extend a canonical three variable macro mode to include a bond market, consisting of a fiscal rule and a bond demand schedule for long-term government bonds. To identify the model in the presence of political uncertainty and forward-looking investors, we derive an external instrument for bond demand shocks from a novel news ticker data set. Our main results are threefold. First, the interaction between fiscal policy and bondholders’ expectations is critical for the evolution of prices. Fiscal policy reinforces contractionary monetary policy through sustained increases in primary surpluses and investors provide incentives for “passive” fiscal policy. Second, investors’ expectations matter for inflation, and we document a Fisherian response of inflation across all maturities in response to a bond demand shock. Third, domestic politics is critical in the determination of bondholders’ expectations and an increase in the perceived riskiness of sovereign debt increases inflation and thus complicates the task of controlling price growth.
Read article
Eine Hochfrequenzanalyse zur Abgrenzung von überlagernden Effekten am Beispiel des Ausfallrisikos italienischer Staatsanleihen
Ruben Staffa
Wirtschaft im Wandel,
No. 2,
2023
Abstract
Die wirtschaftliche Aktivität und das Ausfallrisiko staatlicher Schulden beeinflussen sich gegenseitig. Sinkt die wirtschaftliche Aktivität einer Volkswirtschaft, steigt wegen fallender Steuereinnahmen das Risiko, dass der Staat Zinszahlungen und Tilgungen auf Staatsanleihen nicht zurückzahlen kann. Umgekehrt kann das staatliche Ausfallrisiko seinerseits die wirtschaftliche Aktivität beeinflussen. Steigt das Ausfallrisiko, geraten Banken unter Druck, die Staatsanleihen in ihren Bilanzen führen, und reduzieren die Kreditvergabe an Unternehmen. In der Konsequenz sinkt die wirtschaftliche Aktivität. Dieser Beitrag nutzt hochfrequente News-Ticker-Daten zur Ableitung politischer Ereignisse und davon ausgelöster Fluktuationen im Staatsschuldenrisiko. Diese allein politisch bedingten Fluktuationen ermöglichen es, den Effekt des Staatsschuldenrisikos auf die wirtschaftliche Aktivität zu messen, ohne dass die Schätzung von der gegenläufigen Beziehung der Variablen beeinträchtigt wird. Das Vorgehen wird am Beispiel Italiens erläutert.
Read article
The Cleansing Effect of Banking Crises
Reint E. Gropp, Steven Ongena, Jörg Rocholl, Vahid Saadi
Economic Inquiry,
No. 3,
2022
Abstract
We assess the cleansing effects of the 2008–2009 financial crisis. U.S. regions with higher levels of supervisory forbearance on distressed banks see less restructuring in the real sector: fewer establishments, firms, and jobs are lost when more distressed banks remain in business. In these regions, the banking sector has been less healthy for several years after the crisis. Regions with less forbearance experience higher productivity growth after the crisis with more firm entries, job creation, and employment, wages, patents, and output growth. Forbearance is greater for state-chartered banks and in regions with weaker banking competition and more independent banks.
Read article
Regionale Effekte einer durch einen Lieferstopp für russisches Gas ausgelösten Rezession in Deutschland
Oliver Holtemöller, Axel Lindner, Christoph Schult
IWH Policy Notes,
No. 1,
2022
Abstract
Ein Stopp der russischen Gaslieferungen würde zu einer Rezession der deutschen Wirtschaft führen. Nicht alle Regionen wären davon gleich betroffen: Vor allem wäre dort, wo das Verarbeitende Gewerbe ein großes Gewicht hat, mit einem deutlich stärkeren Einbruch der Wirtschaftsleistung zu rechnen als andernorts. Deshalb wäre Westdeutschland und dort insbesondere der Süden stärker betroffen als der Osten Deutschlands. Dagegen spielt für die Frage, wie viele Arbeitsplätze durch einen bestimmten Rückgang der Wertschöpfung gefährdet sind, die Höhe der Arbeitsproduktivität eine ausschlaggebende Rolle.
Read article
