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.
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The Effect of Different Saving Mechanisms in Pension Saving Behavior: Evidence from a Life-Cycle Experiment
Martin Angerer, Michael Hanke, Ekaterina Shakina, Wiebke Szymczak
Journal of Risk and Financial Management,
No. 5,
2025
Abstract
We examine how institutional saving mechanisms influence retirement saving decisions under bounded rationality and income risk. Using a life-cycle experiment with habit formation and loss aversion, we test mandatory and voluntary binding savings under deterministic and stochastic income. Voluntary commitment improves saving performance only when income is predictable; under uncertainty, it fails to improve performance. Mandatory savings do not raise total saving, as participants reduce voluntary contributions. These results emphasize the role of income smoothing in enabling behavioral interventions to improve long-term financial outcomes.
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Within-Country Inequality and the Shaping of a Just Global Climate Policy
Marie Young-Brun, Francis Dennig, Frank Errickson, Stéphane Zuber
Proceedings of the National Academy of Sciences of the United States of America (PNAS),
No. 39,
2025
Abstract
Climate policy design must balance emissions mitigation with concerns for fairness, particularly as climate change disproportionately affects the poorest households within and across countries. Integrated Assessment Models used for global climate policy evaluation have so far typically not considered inequality effects within countries. To fill this gap, we develop a global Integrated Assessment Model representing national economies and subnational income, mitigation cost, and climate damage distribution and assess a range of climate policy schemes with varying levels of effort sharing across countries and households. The schemes are consistent with limiting temperature increases to 2 °C and account for the possibility to use carbon tax revenues to address distributional effects within and between countries. We find that carbon taxation with redistribution improves global welfare and reduces inequality, with the most substantial gains achieved under uniform taxation paired with global per capita transfers. A Loss and Damage mechanism offers significant welfare improvements in vulnerable countries while requiring only a modest share of global carbon revenues in the medium term. The poorest households within all countries may benefit from the transfer scheme, in particular when some redistribution is made at the country level. Our findings underscore the potential for climate policy to advance both environmental and social goals, provided revenue recycling mechanisms are effectively implemented. In particular, they demonstrate the feasibility of a welfare improving global climate policy involving limited international redistribution.
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‘And Forgive Us Our Debts’: Christian Moralities and Over-indebtedness
Iftekhar Hasan, Konstantin Kiesel, Felix Noth
Journal of Financial Research,
Fall
2025
Abstract
This paper analyses whether Christian moralities and rules formed differently by Catholics and Protestants impact the likelihood of households to become overindebted. We find that over-indebtedness is lower in regions in which Catholics outweigh Protestants, indicating that Catholics‘ forgiveness culture and a stricter enforcement of rules by Protestants serve as explanations for our results. Our results provide evidence that religion affects the financial situations of individuals and show that even 500 years after the split between Catholics and Protestants, the differences in the mind-sets of both denominations play an important role for situations of severe financial conditions.
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13.03.2025 • 10/2025
A turning point for the German economy?
The international political environment has fundamentally changed with looming trade wars and a deteriorating security situation in Europe. The leading parties in Germany are setting the stage for debt-financed additional defence tasks with far-reaching changes to the debt brake. This entails major risks for the German economy, but also opportunities. Meanwhile, the economy continues to be in a downturn. According to the spring forecast of the Halle Institute for Economic Research (IWH), gross domestic product (GDP) in 2025 is likely to be roughly the same as in the previous year, and it will not increase significantly until 2026, partly because uncertainty about German economic policy is likely to decrease after the new government is established, meaning that the savings rate of private households will fall again somewhat and the debt-financed additional government spending will gradually have an impact on demand. The IWH economists are forecasting an increase in GDP of 0.1% for 2025. In December, they were still forecasting growth of 0.4% for 2025. The outlook is similar for East Germany, where production is likely to have increased slightly in 2024, unlike in Germany as a whole.
Oliver Holtemöller
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Banks and the State-Dependent Effects of Monetary Policy
Martin S. Eichenbaum, Federico Puglisi, Sergio Rebelo, Mathias Trabandt
NBER Working Papers,
No. 33523,
2025
Abstract
We show that the response of banks’ net interest margin (NIM) to monetary policy shocks is state dependent. Following a period of low (high) Federal Funds rates, a contractionary monetary policy shock leads to an increase (decrease) in NIM. Aggregate economic activity exhibits a similar state-dependent pattern. To explain these dynamics, we develop a banking model in which social interactions influence households’ attentiveness to deposit interest rates. We embed that framework within a nonlinear heterogeneous-agent NK model. The estimated model accounts well quantitatively for our key empirical findings.
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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 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.
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Economic Outlook
IWH Economic Outlook 2026 Slight Upturn on the Horizon, Structural Problems Remain December 11, 2025 As the year draws to a close, it remains uncertain whether the German economy…
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East Germany
The Nasty Gap 30 years after unification: Why East Germany is still 20% poorer than the West Dossier In a nutshell The East German economic convergence process is hardly…
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The Distribution of National Income in Germany, 1992-2019
Stefan Bach, Charlotte Bartels, Theresa Neef
IWH Discussion Papers,
No. 25,
2024
Abstract
This paper analyzes the distribution and composition of pre-tax national income in Germany since 1992, combining personal income tax returns, household survey data, and national accounts. Inequality rose from the 1990s to the late 2000s due to falling labor incomes among the bottom 50% and rising incomes in the top 10%. This trend reversed after 2007 as labor incomes across the bottom 90% increased. The top 1% income share, dominated by business income, remained relatively stable between 1992 and 2019. A large share of Germany’s top 1% earners are non-corporate business owners in labor-intensive professions. At least half of the business owners in P99-99.9 and a quarter in the top 0.1% operate firms in professional services – a pattern mirroring the United States. From 1992 to 2019, Germany’s top 0.1% income concentration exceeded France’s and matched U.S. levels until the late 2000s.
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