Welcome to my website! I am working as an economist at the World Bank studying topics related to the intersection of macroeconomic and fiscal policies with the clean energy transition and climate change. At the World Bank, I am currently working on developing a fiscal framework to facilitate a sustainable, equitable, and growth-oriented clean energy transition in Latin America. Additionally, I am a PhD candidate at the Humboldt University of Berlin.
You can contact me at goethann@hu-berlin.de
"Capital Adjustment Costs and Stranded Assets in an Optimal Green Energy Transition" - (with Leopold Zessner-Spitzenberg & Michael Burda - IZA Discussion Papers 18356, Institute of Labor Economics (IZA).
Abstract
In the context of a green energy transition, capital adjustment costs render effective substitution between clean and dirty energy sources finite and endogenous, despite infinite long-run substitutability. Ramsey optimal paths robustly frontload clean investment before exhaustion of a given carbon budget, but also generally imply some capital stranding. Along the path of emissions reduction, new investment is quantitatively more important than reduced output or labor redeployment. An ambitious climate goal in our benchmark calibration implies modest levels of stranded capital at 1.5% of GDP, but this rises to more than 7% if implementation is delayed by a decade.
"Capital Adjustment Costs and Nationally Determined Contributions - How to Avoid Double Transitions of Energy Capital?" (with Leopold Zessner-Spitzenberg & Carolyn Fischer - Draft Available Upon Request)
Abstract
Emission-intensive energy technologies still hold a productivity advantage, but this gap is rapidly closing. Delaying the energy transition forces a faster build-up of clean capital later, raising adjustment costs through congestion and scarcity of specialized resources. Minimizing these costs requires balancing this intertemporal trade-off, which differs between developing and advanced economies. Using a state-of-the-art growth model with detailed sectoral calibration, we identify optimal transition paths for India and the EU. In India, rising demand and clean-technology catch-up drive immediate clean investment, with modest carbon pricing preventing a double transition of its energy capital stock. In the EU, given the limited remaining carbon budget, decommissioning the high-emission legacy capital stock must begin immediately, when the productivity gap is still greatest. A higher carbon price is therefore needed to render clean investment competitive early in the transition. For both the EU and India, ambitious climate policy entails modest welfare losses.
"Supply Shocks at the Zero Lower Bound: Evidence from Japan." (Draft Available Upon Request)
Abstract
Using Japan’s long-lasting experience at the zero lower bound (ZLB), we empirically investigate whether the effects of supply shocks depend on the monetary policy stance. I construct a novel utilization-adjusted total factor productivity series and use smooth local projections to estimate state-dependent impulse responses. Broadly in line with the textbook New Keynesian model, I provide robust evidence that in response to a positive supply shock, output increases less at the ZLB compared to periods of unconstrained monetary policy. My results do not support the expected inflation channel as the primary underlying driver. Instead, I argue that a "wage-consumption-confidence channel" and a "financial accelerator channel" might be important for understanding monetary policy-dependent output responses to supply shocks.
" Modelling Capital Adjustment Costs for the Clean Green Energy Transition" (Draft Available Upon Request)
Abstract
Capital adjustment costs are central to modeling aggregate investment dynamics, but there is no systematic and consistent comparison of different specifications in a macroeconomic model. This paper combines a systematic review of empirical estimation strategies—reporting parameter values ranging from 0.001 to 20—with a quantitative analysis of how gross versus net investment based adjustment costs shape optimal investment in the clean energy transition of the EU. Applying adjustment costs to gross investment sharply raises transitional welfare losses, as replacement investment becomes costly. Particularly for non-energy capital, which accounts for 80% of the EU stock, replacement-related costs reach up to 2.5% of GDP. In contrast, net-based costs make capital depreciation expensive, causing about 0.03% of GDP in adjustment costs. Under partial irreversibility, stranded fossil fuel related capital increases by about 11 percentage points and dirty energy taxes need to be around 70 percent higher.
"Taxing and Subsidizing Energy in Latin America and the Caribbean: Insights from a Total Carbon Pricing Approach" (with Daniel Navia Simon, Carolina Mejia-Mantilla & Ruth Llovet Montañes)
Blog: "Rethinking Energy Taxation and Subsidies in the LAC region: Achieving More than One Goal" (with Daniel Navia Simon, Carolina Mejia-Mantilla & Ruth Llovet Montañes)
Box in the State and Trends of Carbon Pricing 2025 report of the World Bank Group (with Daniel Navia Simon, Carolina Mejia-Mantilla & Ruth Llovet Montañes)
"Roadmap for Energy Taxation Reforms in Peru" (with Daniel Navia Simon - Draft Available Upon Request)
"Anchoring Carbon Price Expectations" (with Leopold Zessner-Spitzenberg - Draft Available Upon Request)
Abstract
We study the channels through which carbon prices shape the transition of the energy system to renewable sources in an economic growth model with a limit on cumulative emissions calibrated to Peru. Carbon prices immediately induce a reduction in energy intensity of output and an increase in capacity utilization of renewable energy infrastructure. The quantitatively most important channel, however, is the effect of carbon prices on long-lived and hard-to-adjust energy infrastructure. The long planning horizon of infrastructure investment implies that expected future carbon prices are crucial for an efficient energy transition. We illustrate this result by comparing transition paths for expected and unexpected increases in ambition of climate targets. We find that the latter causes a far larger economic disruption, as it does not provide adequate incentives for energy infrastructure investment ex-ante.