2026

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2026-18

ZICO: A Credit Scoring Approach to Detecting Zombie Papers

Christophe Hurlin, Marc Joëts, Valérie Mignon

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Abstract
This paper proposes a new framework for assessing scientific credibility using probabilistic retraction risk. We introduce the Zombie Integrity and Credibility Oversight (ZICO) framework, a multidimensional credibility score inspired by credit-scoring models in finance. Rather than relying on isolated indicators of misconduct, ZICO integrates heterogeneous signals extracted from the semantic characteristics of scientific manuscripts and the broader organization of scientific production to estimate the ex ante probability that a publication will eventually become problematic or be retracted. We apply the framework to a corpus of publications in economics and finance. Our findings show that retraction risk is driven primarily by linguistic and semantic characteristics rather than by conventional metadata, such as authorship or institutional affiliations. In particular, measures of readability, lexical diversity, textual complexity, and citation practices emerge as the strongest predictors of scientific credibility. These signals capture deeper structural and stylistic irregularities rather than differences in English language proficiency, thereby highlighting semantic organization as a robust marker of research integrity. We further develop a dynamic version of ZICO that continuously updates credibility assessments, allowing the framework to operate as an adaptive early-warning system for editorial screening. More fundamentally, our framework shifts the assessment of scientific integrity from the ex post detection of misconduct to the ex ante probabilistic evaluation of manuscript credibility. Beyond its predictive performance, ZICO provides a transparent and interpretable framework for editorial decision-making, research evaluation, and the governance of research integrity.
Mot(s) clé(s)
Zombie papers; Research integrity; Retraction risk; Scientific publishing; Natural language processing; Machine learning.
2026-17

A GDP-neutral climate vulnerability index for improved environmental risk assessment and adaptation policy

David Dosso, Imen Ghattassi, Francisco Serranito

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Abstract
Climate vulnerability indices are widely used to guide environmental planning, climate adaptation strategies, and the allocation of resilience resources. However, many existing indicators are strongly correlated with countries’ levels of economic development, which can blur the distinction between climate risk and income conditions and lead to potentially biased prioritization of adaptation efforts. This study introduces the Climate Vulnerability Neutral (CVN) Index, a transparent and reproducible tool designed to better isolate climate-related vulnerability while maintaining broad sectoral coverage relevant for environmental management. The CVN index is constructed using a systematic selection procedure that retains vulnerability components with limited dependence on GDP per capita while preserving representation across key environmental domains, including food security, water resources, health, ecosystems, habitat, and infrastructure. Using panel data for 158 countries over the period 1995-2023, the results show that economic development explains a substantial share of the variation in widely used vulnerability indicators, whereas its influence on the CVN index is markedly lower. The proposed framework therefore provides a more balanced representation of countries’ exposure and sensitivity to climate hazards across income groups.
From a management perspective, the CVN index offers a practical instrument for monitoring vulnerability trends, supporting comparative risk assessments, and improving the targeting of climate adaptation policies. By enhancing the transparency and usability of vulnerability measurement, the index can assist governments and international organizations in designing more effective and evidence-based environmental management strategies.
Mot(s) clé(s)
Climate vulnerability ; Environmental management ; Risk assessment ; Adaptation policy ; Composite indicators, GDP neutrality
2026-16

The Customer Is Always Right? How LLMs and Humans Judge Discrimination

Matthieu Bunel, Marie-Noëlle Lefebvre, Elisabeth Tovar

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Abstract
This paper studies how large language models (LLMs) trade off moral norms against economic incentives in discriminatory hiring decisions. Bridging discrimination economics and the literature on the moral alignment in computer science, we submit 18 frontier and local LLMs to the factorial vignette experiment of a published human survey that manipulates the motive of discrimination (customer taste-based versus statistical), the cost of non-discrimination, and explicit moral injunctions. We extend this design with LLM-relevant factors: model and user personas, reasoning instructions, scenario realism, and conversational memory. In line with the literature, we find that LLMs align with humans in the direction of the effects manipulated in the survey; we also find important inter-model heterogeneity. Beyond, we contribute to the literature with, to the best of our knowledge, five novel results: 1) the market-oriented motive (customer-taste) overwhelmingly sways models in favour of discrimination, much more than what happens for human respondents; 2) models are more polarised than humans in response to moral injunctions; 3) classic prompt engineering interventions (user stated motives and model personas) have a weak impact on the models’ “moral compass”; 4) post-training alignement, not scale, shape inter-model heterogeneity, which means that de-biasing is possible but must be explicitly implemented by model providers and 5) memory effects suggest that moral permissivity in the models can be induced by conversational contextual effects.
Mot(s) clé(s)
Moral judgment on discrimination ; Artificial intelligence ; LLM audit
2026-15

When Does Uncertainty Become Expansionary? The Role of Composition and State Dependence

Nicolas Himounet, Francisco Serranito, Julien Vauday

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Abstract
When does uncertainty become expansionary? While the empirical literature generally concludes that uncertainty depresses economic activity, recent theoretical contributions suggest that some forms of uncertainty may instead stimulate investment and output. This paper argues that the macroeconomic effects of uncertainty depend jointly on its composition and the prevailing uncertainty regime. Using sixteen U.S. uncertainty indicators over the period 1990–2024, we construct two orthogonal latent factors through principal component analysis. The first captures the overall level of uncertainty, whereas the second distinguishes financial from non-financial uncertainty. An independent VARIMAX rotation validates this interpretation. We then estimate state-dependent local projections to examine how different uncertainty shocks affect industrial production and employment across low-, moderate-, and high-uncertainty regimes. We find that financial uncertainty shocks generate the conventional contractionary effects. In contrast, non-financial uncertainty shocks significantly increase economic activity when aggregate uncertainty is moderate or high, while they have no significant effect during low-uncertainty periods. These findings suggest that the composition of uncertainty is a key determinant of its macroeconomic consequences and provide new aggregate evidence supporting recent theories predicting expansionary effects of non-financial uncertainty.
Mot(s) clé(s)
Uncertainty, Financial uncertainty, Local projections, State dependence, Principal component analysis.
2026-14

The Well-Being Costs of Low Emission Zones: Evidence from London's ULEZ Expansions

Corin Blanc

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Abstract
In response to rising urban air pollution, European cities have adopted Low Emission Zones (LEZs), restricting the most polluting vehicles. While effective in improving air quality, these policies remain controversial due to concerns over fairness and acceptability. This paper examines the impact of London’s 2021 and 2023 Ultra Low Emission Zone (ULEZ) expansions on Subjective Well-Being (SWB). Using panel data from the UK Household Longitudinal Study and a staggered difference-in-differences design with individual and year fixed effects, we compare changes in life satisfaction among residents inside and outside the affected areas. We find that the 2021 expansion led to a decline in life satisfaction by approximately 0.4 points. We explore the mechanisms driving this decline and find that the well-being loss is mediated by car dependency and transport mode availability. While the policy increased reliance on public transport, we show that a better accessibility to public transport mitigates the decline in life satisfaction among London residents. Furthermore, we show that the well-being costs of the policy are regressive, disproportionately affecting lower-income households. These findings suggest that LEZs can generate short-term and unequal well-being costs despite achieving modest behavioural change, highlighting the need for complementary measures to enhance social acceptability.
Mot(s) clé(s)
Low Emission Zones (LEZs), Air pollution, Environmental policy, Subjective well-being, Life satisfaction, Staggered Difference-in-differences, Social acceptability
2026-13

A note on strategic ambiguity and coalition structure in electoral competition

Aswin Sivapragassam

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Abstract
We revisit the two-candidate, three-alternative election campaign game with strategic ambiguity of Aragones & Postlewaite (2002), in which ambiguity arises in equilibrium when no pure alternative is majority-winning and voters exhibit sufficiently intense preferences. We show that the existence condition for winning strategies of the candidate associated with the Condorcet alternative is not sufficient for the existence of such a strategy. The original derivation evaluates the worst-case opponent strategy only at two extreme points of the feasible set, whereas the relevant bound is attained elsewhere. We provide a counterexample showing that the original condition can be satisfied even though no winning strategy exists, and derive a corrected characterization: winning strategies rely on voters who most prefer the remaining alternative, associated with neither candidate, rather than those who rank the Condorcet alternative second. This mirrors the coalition logic of the non-Condorcet candidate, yielding a structural symmetry between the two candidates’ equilibrium strategies. As a consequence, association with a Condorcet alternative does not confer a systematic strategic advantage, and strategic ambiguity operates as a selective rather than aggregative electoral device.
Mot(s) clé(s)
Strategic ambiguity, Condorcet winner, Electoral competition, Coalition structure, Voting
2026-12

What Drives Mineral Commodity Prices? A Historical Perspective on Demand and Supply Dynamics

Romain Capliez, Carl Grekou, Emmanuel Hache, Valérie Mignon

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Abstract
This paper investigates the historical determinants of real mineral commodity prices using a structurally identified vector autoregression (SVAR) with incomplete identification. Drawing on a large sample of mineral commodities covering more than a century of data, we identify supply, aggregate demand, and metal-specific demand shocks using economically motivated prior distributions. Historical decompositions show that price fluctuations are predominantly driven by demand-side forces, with metal-specific demand shocks accounting for the largest share of variation. Aggregate demand shocks also play an important role, particularly during periods of global instability, while the contribution of supply shocks is more limited and tends to decline over time. Elasticity estimates indicate that prices respond more strongly and more persistently to demand shocks than to supply shocks, whereas supply responses remain weak in the short run. We also document substantial heterogeneity across mineral commodities and over time, reflecting differences in adjustment mechanisms across markets. Overall, our findings highlight the central role of demand in mineral commodity price formation and provide little support for the view that increasing scarcity has been the dominant force shaping observed price dynamics over the period considered. Instead, fluctuations in mineral commodity prices appear to be primarily driven by demand-side factors rather than by tightening supply conditions.
Mot(s) clé(s)
Mineral commodities; Commodity price dynamics; Resource scarcity; Structural VAR; Historical decomposition
2026-11

Intergenerational Redistribution in the Green Transition

Barbara Annicchiarico, Jean-Guillaume Sahuc, Gauthier Vermandel

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Abstract
We study the intergenerational distributional effects of carbon pricing during the green transition in an overlapping-generations New Keynesian model calibrated to euro-area household micro data. Climate policy generates systematic redistribution across cohorts through two channels: a labor-income channel, driven by wage compression and lower labor demand, and a financial-wealth channel, driven by asset revaluation and higher real returns. The labor- income channel dominates quantitatively , generating persistent welfare losses of up to 6 percent in permanent-consumption equivalents for working-age households, while retirees experience comparable gains. Revenue recycling can mitigate these asymmetries, requiring 40 to 68 per- cent of carbon-tax revenues to be directed toward financial-income tax relief. Monetary policy has limited influence on the overall redistributive pattern.
Mot(s) clé(s)
Climate policy , carbon pricing, intergenerational redistribution, overlapping generations, fiscal policy , New Keynesian model
2026-10

Interconnection as Climate Policy? Assessing the impact of the EU 15% interconnection target on CO₂ Emissions with PyPSA-Eur

Amady Léchenet

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Abstract
This paper assesses whether the European Union’s target of achieving 15% cross-border electricity interconnection by 2030 can ease the mitigation of CO2 emissions. Using the open-source Python for Power System Analysis (PyPSA)-Eur modeling framework, we develop a large scale linear optimization model of power systems of France, Germany, Belgium, the Netherlands, and Luxembourg. The model endogenously optimizes generation, storage, and transmission capacities under technical constraints, while incorporating policy constraints in the form of both a minimum interconnection requirement and alternative CO2 emission caps. Our results show that implementing the interconnection target alone yields only marginal carbon reductions relative to the baseline. Although 15% is not cost-optimal for each country, significant changes in electricity generation and decreases in Greenhouse Gas (GHG) emissions are obtained with enhanced cross-border interconnections. Grid development significantly facilitates deeper decarbonization by enabling higher renewable penetration, reducing flexible fossil-based generation, and reshaping cross-border electricity flows.
Mot(s) clé(s)
Market coupling, cross-border interconnection, CO₂ mitigation, power system optimization, Renewable Energy Sources (RES) integration
2026-9

Les systèmes nationaux de protection sociale alimentaire. Comparaison structurale France-Brésil

Adam POUPARD

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Abstract
This article offers structural definition and comparison of national food social protection systems (SNPSA) in France and Brazil by applying Théret’s (1997) description of social protection systems to the food sector. We describe SNPSA as a mediating force between economic, political, and reproductive orders in the face of the joint commodification of land and food. The analysis shows that the two countries represent two opposing ideal types through an examination of the frameworks mobilized in the formulation of public policies, by combining inductive and structural analysis. France represents a historically weak alliance between the reproductive and political spheres in terms of access to food, whereas in Brazil this constitutes a key basis for legitimizing the actions of the federal government. We explain these differences based on the synchronies and asynchronies of popular and rural social movements.
Mot(s) clé(s)
Social protection for Food, France-Brazil comparison, commodification, institutionalization of food policies, Food Security
2026-8

The Natural Resources Curse and Critical Raw Materials: Comparing Dependence and Abundance Measures

Noé Viguié

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Abstract
This paper revisits the Natural Resource Curse (NRC) in the case of Critical Raw Materials (CRM), a strategic input for the energy transition. Using USGS production data for 1970–2019, we distinguish between dependence (CRM production as a share of GDP) and abundance (CRM production per capita). We argue that dependence is endogenous and a misleading proxy of resource endowment. Our cross-sectional model averaging shows no robust impact of CRM on growth, while primary export dependence has only a fragile, time-sensitive negative effect. Panel estimations for 44 countries, using advanced static and dynamic estimators, point to the same conclusion: weak and inconsistent results, with the apparent negative effect of CRM dependence largely driven by endogeneity. Overall, our findings reject the idea of a universal CRM curse. Instead, they highlight how measurement choices and endogeneity critically shape the NRC debate. While appropriate policies should address potential negative externalities and encourage diversification as well as the capture of greater value added along the CRM supply chain, our findings suggest that, to ensure long-term growth, traditional factors–such as human capital accumulation, infrastructure, and
institutional quality and stability–should remain central.
Mot(s) clé(s)
natural resources curse; critical raw materials; natural resources abundance; natural resources dependence
2026-7

Hydrogen in financial markets: A hybrid asset at the crossroads of technology and clean energy

Emilie Couture

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Abstract
Hydrogen is increasingly presented as a key solution for decarbonization in the context of the energy transition. This paper investigates how financial markets perceive hydrogen-related companies and whether these assets display distinct financial behaviors compared to other clean energy sectors—namely solar, wind, and renewable energy producers. Using daily data and a multi-faceted econometric approach, accounting for non-linearities, long-run dynamics, and time-varying correlations, we analyze both returns and dynamic correlations of hydrogen stocks relative to other energy segments. Our results show that hydrogen indices behave more like speculative technological assets than mature renewable energy sources. Their returns are more sensitive to financial stress indicators (e.g., the VIX) and to the performance of technology stocks. Dynamic correlations with other energy sectors are shaped by macroeconomic conditions: oil prices act as a synchronizing factor, while gold increases returns but reduces correlations. In contrast, geopolitical and financial uncertainty tends to increase comovements, reflecting flight-to-safety behavior. These findings highlight hydrogen’s hybrid identity in financial markets—volatile, innovation-driven, and not yet integrated into the traditional renewable asset class, raising implications for both investors and policymakers regarding the financial interconnectedness and strategic support of the hydrogen sector within the broader clean energy transition.
Mot(s) clé(s)
Hydrogen, Renewable energy, Asset pricing, Stock returns, Cross-market correlations
2026-6

Is It Over Now? (Giver's Version): Financial Giving, Economic Shocks, and Resilience to Depression in Older Europeans

Arielle Cohen Tanugi

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Abstract
This study examines whether providing financial transfers influences depressive symptoms among older European adults and explores whether income or wealth shocks moderate this relationship. Using longitudinal data from the Survey of Health, Aging, and Retirement in Europe (SHARE) and a staggered dynamic Difference-in-Differences approach, this work assesses the psychological consequences of financial giving across diverse socioeconomic contexts. Results indicate that while giving initially leads to a decline in mental well-being, this effect diminishes over time, suggesting an adjustment process rather than lasting distress. The negative impact is strongest among women and those still employed, while retirees experience weaker effects. Contrary to expectations, negative income and wealth shocks do not significantly amplify depressive symptoms, implying that financial strain alone does not drive the relationship between giving and mental health. Instead, financial giving appear to be shaped by long-term social commitments, moral obligations, and ingrained norms rather than short-term economic considerations. These findings remain robust when combining propensity score matching with the staggered dynamic Difference-in-Differences estimation.
Mot(s) clé(s)
Intergenerational Transfers, Financial Transfers, Mental Health, Wealth Shocks, Income Shocks
2026-5

Maritime traffic specialization and environmental health impacts in European port cities

Charbel ALKHOURY, César Ducruet, Magali Dumontet, Mariantonia Lo Prete, Barbara Polo Martin, Ling Sun, Sheng Zhang

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Abstract
This paper investigates the influence of multiple vessel traffics on air pollution and public health in European port cities. A sample of 120 Functional Urban Areas (FUAs) is analysed over the period 2000-2019, confronting container, cruise, liquid bulk, and solid bulk traffic with environmental (emissions of CO², PM2.5, NO²), public health (life expectancy, mortality rate), and socio-economic features like population density and GDP per inhabitant. Results from the fixed effects model show that population density is the major cause of all pollutions, followed by GDP and solid bulks, while life expectancy and mortality are mainly influenced by the nature of the local socio-economic environment (population density, age, GDP, bed rates, educational level). This is complemented by a factor analysis and a hierarchical clustering, which reveal the existence of three types of port cities: critical, tourism, and metropolitan. The typology of port cities is further discussed based on ground observation in particular sites.
Mot(s) clé(s)
Europe; Functional Urban Area; hinterland; port city; sea transport; specialization; supply chains
2026-4

The Unequal Burden of Heat: Spatial Heterogeneity in Productivity Responses in French Agriculture

Thomas Jacquet

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Abstract
This article assesses the short- and medium-term effects of extreme heat on agricultural productivity across French departments during 1980-2023. Using high-resolution ERA5-Land temperature data and CORINE Land Cover, we construct a sector-specific Extreme Degree Days (EDD) index, weighted by cropland and pasture shares to capture sector-specific thermal stress. We estimate department-specific impulse responses via local projections and find significant and persistent productivity losses following heat shocks above 29 °C, with effects intensifying over a four-year horizon and attenuating only modestly thereafter. A Wald test confirms substantial regional heterogeneity in sensitivity to extreme temperatures. The negative impacts are particularly pronounced in lower-productivity, livestock-oriented departments clustered between 44.5° and 46° north latitude. These findings underscore the macroeconomic relevance of a spatially disaggregated measure of exposure to extreme temperatures and highlight the urgency of region-specific adaptation strategies as these episodes intensify.
Mot(s) clé(s)
Agriculture; Climate change; Extreme heat; France; Productivity
2026-3

Fostering energy transition and transport fluidity in European port cities

César Ducruet, Mariantonia Lo Prete

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Abstract
Europe as a whole is often regarded as a frontrunner in the domain of port-city sustainability, thanks to a wide set of international, national, and local initiatives. This paper is a review of local initiatives that are either individual (single port city) or collective (partnerships among several port cities), in the domains of energy transition and transport fluidity. We find that individual initiatives concentrate in northern Europe, in the largest ports, and at a few southern ones like Valencia or Marseilles. Conversely, collective actions are more concentrated in the south, including mostly small and medium-sized port cities, through projects financed by the European Commission. Besides, we show that port-urban congestion and PM2.5 pollution concentrate in the demographically and logistically largest port cities, which also dominate container throughput rankings and have the highest number of initiatives. We discuss the imperatives of ensuring a better regional balance across the continent and its port-city hierarchy.
Mot(s) clé(s)
congestion; energy transition; Europe; population exposure; port cities; transport fluidity
2026-2

Towards a Demand for Money Measurement ? Application to the German hyperinflation of the early 1920s

Georges Prat

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Abstract
An accounting measure of the demand for money is deduced from the Allais’ “Fundamental Equation of Monetary Dynamics”. Data from German hyperinflation in the early 1920s illustrate the method we propose. The spread between money supply and money demand is found to be rather moderate but is not white noise. Our approach can be applied to any country and over any period, provided that the aggregate expenditure can be approximated using available data. This new way can help improve the estimation of the money demand function while avoiding arbitrary assumptions about the dynamics of the spread between money supply and money demand.
Mot(s) clé(s)
demand for money, measure
2026-1

Low-Carbon Hydrogen Deployment Under Trade Liberalization Policies

Benjamin Trouve

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Abstract
Reaching global net-zero by 2050 requires rapidly scaling low-carbon hydrogen, but deployment is hindered by market uncertainty, high capital costs, and weak supply-demand coordination. This paper examines whether liberalizing international hydrogen and ammonia trade can accelerate deployment and how such policies interact with technological innovation. We develop a hybrid framework combining a global TIMES-based energy-system model (KiNESYS-IFPEN) with a stochastic logistic diffusion model calibrated to historical renewable energy growth under imperfect expectations. We find that trade liberalization alone has limited global impact, and mainly reallocates production geographically: the Middle East, North America, Latin America, and China expand as exporters, while Asia Pacific, Europe and Africa become structural importers. Innovation-driven electrolyzer cost reductions raise significantly global deployment success shifting production toward electrolysis. When policies are combined, innovation dominates, while trade openness reinforces regional specialization. These results underscore the central role of technological progress, credible expectations, and the trade-off between cost-efficient specialization and hydrogen supply security.
Mot(s) clé(s)
Hydrogen, Trade Policies, Technology diffusion, TIMES-Markal model.
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