2025

Yesterday at 14 h 41 min

WP 2025.04 Agricultural Productivity Growth and Deforestation in the Tropics

Mathieu Couttenier – Sebastien Desbureaux – Raphael Soubeyran

Abstract

We analyze the impact of agricultural productivity growth on tropical deforestation. Our dynamic model of forest-to-farmland conversion incorporates costs and market constraints on agricultural output, emphasizing that productivity growth, rather than its absolute level, shapes deforestation patterns. Addressing the Jevons’ paradox and Borlaug hypothesis, the model predicts that rising agricultural productivity, reflected by declining fertilizer price growth, has an ambiguous effect on deforestation. Using tropical forest loss data (2000-2022) and fertilizer price variations, we find a negative correlation between fertilizer price growth and deforestation, particularly in regions with high market potential. Without the 10% annual rise in fertilizer prices over the period, deforestation rates would have been 57% faster, representing 6.6 million additional hectares annually. Conversely, the 3% annual increase in crop prices has a minimal impact on deforestation. Our results highlight that protected areas do not mitigate the adverse effects of fertilizer price growth on deforestation.

WP 2025.03 Fueling the energy transition with fossil (not quite) stranded assets

Aude Pommeret – Francesco Ricci

Abstract

The energy transition requires large quantities for raw materials to build the infrastructure needed to supply electricity from renewable sources. In the meanwhile, climate policies push out of the market some of fossil-based infrastructure, generating stranded assets. However, decommissioned infrastructure constitutes a stock of scrap, from which materials can be recovered and recycled to develop the infrastructure for renewable energy. We use a stylized dynamic model featuring the decommissioning rate as a control variable: it reduces the fossil-based infrastructure available for energy production, but also increases the scrap that offers recycling potential. With this model first we study the effect of recycling possibilities on decommissioning and on the extraction of fossil and mineral resources. Second, we can fully characterize the dynamics of the stock of scrap. Considering recycling of decommissioned fossil-based infrastructure, makes the stranded assets problem less severe, while mitigating the rise in the price of virgin materials.

WP 2025.02 Fair burden-sharing for climate change mitigation: an axiomatic approach

Emma Jagu Schippers – David Lowing

Abstract

A significant challenge in climate change negotiations is establishing a burden-sharing method that all or most governments find fair. Two key fairness principles are emphasized by the United Nations Framework Convention on Climate Change in allocating mitigation efforts: the Polluter-Pays principle (“common but differentiated responsibilities”), suggesting that the countries with the highest greenhouse gas emissions should contribute more, and the Ability-to-Pay principle (“respective capabilities”), suggesting that economically advantaged countries should contribute more. This paper proposes a new burden-sharing method that integrates the Polluter-Pays and Ability-to-Pay principles without resorting to weighted indicators. We provide an algorithmic procedure to implement the method in polynomial time and conduct an axiomatic study to emphasize the significance of our approach.

Finally, we apply our method using worldwide data.

WP 2025.01 Individual vs. collective agglomeration bonuses to conserve biodiversity

Francois Bareille – Raphael Soubeyran

Abstract

Agglomeration bonuses (AB) are payments conditional on the contiguity of landowners’ conservation areas. It is widely accepted that, by encouraging landowners to cooperate, ABs promote more cost-effective biodiversity conservation than homogeneous payments. This article challenges this conclusion by studying the impact of different AB designs, which may or may not encourage cooperation. Specifically, we show that differentiating the bonus between
internal (within-landholding) and external (between-landholdings) boundaries affects AB cost-effectiveness. Using an economic-ecological model and game theory, our simulations on realistic landscapes show that the most cost-effective ABs are those presenting relatively larger internal bonuses. Conversely, ABs with relatively larger external bonuses are less cost-effective, despite fostering cooperation between landowners.