Working papers, publications, and the thesis, grouped by status. Drafts of unpublished work are available on request.
Working papers
The Net Climate Value of Carbon Credits: Pricing Leakage, Time, and Reversal
with Jens Abildtrup, Philippe Delacote, Andreas Kontoleon, Mirco Migliavacca, Ben Filewod, Hannes Böttcher, Tommaso Chiti, Ana Rey, Jurij Diaci, Aleksi Lehtonen, Helga Pülzl, Andreas Schindlbacher, and Miguel A. Zavala · Working paper · Replication code
A forest carbon credit is issued for one tonne of CO₂ kept from the atmosphere, but rarely delivers the full tonne. After on-site verification, three downstream channels — market leakage, finite storage duration, and reversal risk — erode credited carbon, none yet priced together. We calibrate each into one issuance rule, applied to sixteen forest practices across three European biomes with Monte Carlo uncertainty. Only 11–49% survives as net climate value (median 23%), and five schemes over-credit by 32–63%. Storage duration is the largest deduction, yet schemes credit 30- and 100-year contracts identically. Reaching 100 MtCO₂ yr⁻¹ of genuine removals needs 60–200 Mha — approaching or exceeding the EU’s 160 Mha forest estate — while crediting the shortfall at face value over-credits by ~86 MtCO₂e yearly, a $4–28 billion social cost. Rankings and gap signs hold across the discount rate and permanence benchmark. With the EU’s Carbon Removals Certification Framework methodology now adopted, a credit equals a tonne only when leakage, duration, and reversal are priced alongside verification.
Public Preferences over Tropical Carbon Offsets: Moral Distance versus Market Distrust in the EU Land-Sector Gap
Pre-registered study, four countries (France, Germany, Spain, Denmark)
How should Europe close the projected 100 Mt CO₂-eq/year shortfall in its 2030 land-sector target? A pre-registered four-country study (France, Germany, Spain, Denmark) measures public preferences over the institutional composition of forest climate mitigation. Respondents allocate a fixed mitigation budget across configurations differing in institutional mode (public versus private offsetting), location (higher- vs lower-income EU, and non-EU tropical), and forest ownership. An opt-out pivot — randomising the do-nothing baseline between a zero-cost status quo and a residual-damage display valued at the social cost of carbon — recovers a single marginal utility of income, tests its invariance across the two framings, and anchors every welfare contrast. A Mode × Location interaction at tropical locations tests whether the tropical discount reflects tastes (moral-circle decay) or beliefs (distrust of private delivery), extending the over-crediting debate from supply to demand. Secondary contrasts recover the offsetting-versus-direct-reduction wedge, the public–private mode wedge, and a community-ownership premium.
One Divide, Two Countries: Climate Concern Splits Support for Forest Conservation Programmes
with Jens Abildtrup, David W. Shanafelt, Antonello Lobianco, and Harald Vacik · Highly Commended Paper Award, 8th Workshop on Non-Market Valuation (Leeds, 2024)
We study and segment demand for forest conservation programmes across Austria (N=592) and France (N=1,637) using discrete choice experiments combining latent class and mixed logit models with machine-learning screening. The valued programmes leaned on climate change mitigation and adaptation, as well as improved biodiversity protection and recreational value. We find both countries splitting the same way: a supportive majority of about three-quarters, and a remaining more reluctant minority. Climate opinions dominate the sorting: climate fear is the strongest single predictor in Austria — the only one to survive when four climate opinion variables are entered together — and is matched only by climate scepticism in France. Against our expectation, belief in the possibility of halting climate change showed no significant effect. Commune-level vote shares add nothing once climate opinions and demographics are included. Willingness to pay differs sharply between the two groups but is hard to predict within them, so the structure of preferences transfers across countries more readily than its magnitudes.
A Clustering-Initialised Specification Workflow for Latent Class Choice Models
Companion R package: klue
Two models represent preference heterogeneity in choice data: a latent class model (LCMNL) treats the population as discrete segments, a mixed logit (MMNL) as a continuous distribution. Which one a study reports — and, for a latent class model, how many segments and which starting values — is largely the analyst’s choice. These researcher degrees of freedom leave model selection arbitrary and hard to reproduce: the same data can support different segmentation stories. I settle each with a data-driven rule fixed in advance — starting values from clustering respondents’ choice patterns, the number of segments from the Bayesian information criterion (BIC) with an entropy check, and a mixed logit benchmark whose BIC decides between the two. In simulations the clustering rule reaches the best solution found in 82% of runs against 11% for uninformed starts, and holds under the blocked D-efficient designs where standard software’s routines fail; BIC recovers the true segment count in 95% of cases; and the benchmark separates discrete from continuous heterogeneity, flagging segments that would otherwise be spurious. Across five public datasets it reproduces every published reading that takes a stand. Fixing the specification ex ante makes it pre-registrable, turning the choice between LCMNL and MMNL into a confirmatory, hypothesis-testing procedure.
A Hybrid Machine Learning Approach for the Prediction of Forest Stand Growth Under Different Climate Scenarios
with Antonello Lobianco, Nikola Besic, Jean-Daniel Bontemps, and Laurent Hertzog
Publications
Do Individual PES Buyers Care About Additionality and Free-Riding? A Choice Experiment
with Jens Abildtrup, Claire Montagné-Huck, Salomé Gorel, and Anne Stenger · Ecological Economics, 213, 107944 (2023) · DOI
A Review of Forest Management Practices Potentially Suitable for Carbon Farming in European Forests
Chiti, T., Rey, A., Abildtrup, J., Böttcher, H., Diaci, J., Frings, O., Lehtonen, A., Pülzl, H., Schindlbacher, A., & Zavala, M. A. · Journal of Environmental Management, 398, 128391 (2026) · Article
Carbon Farming in the European Forestry Sector
Chiti, T., Rey, A., Abildtrup, J., Böttcher, H., Diaci, J., Frings, O., Lehtonen, A., & Zavala, M. A. · From Science to Policy 17, European Forest Institute (2024) · Report
Productive and Biodiverse: Managing Europe’s Forests for Economic and Ecological Outcomes
Chiti, T., Rey, A., Zavala, M. A., Manrique, S., & Frings, O. · IUFRO Policy Report, International Union of Forest Research Organizations (2026, forthcoming)
PhD thesis
Pricing Credibility: Supply-Side Integrity and Public Acceptability in Nature Markets
AgroParisTech · defence expected December 2026
The thesis asks what makes nature markets credible, in three parts. The first builds the measurement instrument: a specification workflow for latent class choice models. The second studies demand-side legitimacy: who supports forest conservation programmes and carbon offsetting, and how that support depends on the institutions delivering them. The third turns to supply-side integrity: an issuance rule that prices leakage, storage duration, and reversal risk into forest carbon credits.