Template-Type: ReDIF-Paper 1.0 Title: B-Ready for Another Disappointment: Assessing the Doing Business Index's Ability to Reflect Business Environments and Predict Private Investment Flows Abstract: The World Bank's "Doing Business" (DB) report ranked nearly 190 countries on their private-sector business climate from 2003 to 2020, grading countries primarily on de jure regulatory performance. Using panel data for 2010–2014 and 2016–2019, we test whether DB scores are associated with or predictive of private investment flows, measured by both Foreign Direct Investment (FDI) and Gross Fixed Capital Formation (GFCF). Across pooled OLS, two-way fixed-effects, and Jordà local projection specifications, we find no robust relationship between DB score improvements and either investment measure. DB's apparent cross-sectional relevance for GFCF dissolves once institutional fragility is controlled for, revealing the index as a proxy for stability rather than a measure of regulatory quality. Capital account openness is the dominant within-country predictor of domestic investment intensity, a dimension entirely absent from DB's framework. A synthetic index of our construction, combining institutional stability, capital account openness, and trade integration consistently outperforms DB in cross-sectional horse races. These findings carry direct implications for Business-Ready (B-Ready), DB's successor due in late 2026, whose continued reliance on de jure scoring risks reproducing the same structural limitations and ultimately fail to capture the conditions firms actually face. Author-Name: Malo Raballand Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: C23; F21; G18; O43; P48 Keywords: Business-Ready; Doing Business; De jure regulation; Gross Fixed Capital Formation; Foreign Direct Investment; World Bank Number: 2618 Handle: RePEc:aim:wpaimx:2618 Creation-Date: 2026-06-01 Note: Working paper AMSE 2026-18 Note: HAL hal-05666788 File-URL: https://hal.science/hal-05666788/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Macroprudential Policies and Inequalities in Europe: The Role of Household Portfolio Composition Abstract: We study the effects of macroprudential policies on income and wealth inequality across 18 Eurozone countries over the period 2000–2024. We focus on the financially constrained Wealthy Hand-to-Mouth households for whom the regulation changes are likely to be consequential. We present insights from a stylised two-economy incomplete-markets model where the heterogeneity in household portfolio composition shapes the effects on inequalities of borrower-based regulation. Using panel regressions and local projections, we test empirically the model's predictions that macroprudential policies matter for inequalities and their effects differ depending on the concentration of housing or pension assets in the Wealthy Hand-to-Mouth households' illiquid portfolios. The empirical findings underscore that in housing dominant economies, the reduction of the LTV ratio improves wealth inequalities in the short term through a collateral-leverage mechanism, whereas it persistently widens wealth disparities in pension-dominant economies through credit exclusion effects. Author-Name: Marie-Hélène Gagnon Author-Workplace-Name: Université Laval [Québec] Author-Name: Céline Gimet Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Author-Name: Uros Herman Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: D31; E21; E44; G28; R21 Keywords: Loan-to-value regulation; Macroprudential policy; Eurozone; Local projections; Wealthy hand-to-mouth; Heterogeneity; Portfolio; Wealth inequalities Number: 2617 Handle: RePEc:aim:wpaimx:2617 Creation-Date: 2026-06-01 Note: Working paper AMSE 2026-17 Note: HAL hal-05666769 File-URL: https://hal.science/hal-05666769/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: The Biological Endowment Curse Abstract: Standard models of international trade treat factor endowments as exogenous and stable. This paper argues that biological invasions induced by trade itself erode productive endowments, generating a feedback loop from comparative advantage to invasive species pressure and back. We call this mechanism the biological endowment curse : the very endowment that confers comparative advantage in agriculture raises the exposure to invasion, which in turn degrades the endowment. This dynamic cost of trade has been largely absent from the received theory of comparative advantage. We formalise this idea in two steps. First, in a single-country model with Cobb-Douglas endowment dynamics, we establish the existence and global stability of a long-run equilibrium and show that the equilibrium healthy endowment decreases with import pressure and with ecological fragility. Second, in a two-country discrete-time game, we derive closed-form expressions for the Markov Perfect Nash equilibrium and the cooperative solution. Both countries under-invest in biosecurity at Nash, and the under-investment gap is larger for countries with stronger regeneration capacity and greater commercial interdependence. We then characterise the optimal international agreement, modelled as a Nash equilibrium in trigger strategies. A key structural result is that the incentive compatibility constraint reduces to a purely parametric condition, independent of the current state of endowments. When the pure trigger fails, trade linkage can restore viability. Finally, policy implications are discussed. Author-Name: Charles Figuières Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: C73; F11; Q17; Q57 Keywords: Sanitary and Phytosanitary SPS agreements; Biosecurity; Levhari-Mirman; Differential game; Biological endowment curse; Comparative advantage; Factor endowments; Invasive species Number: 2616 Handle: RePEc:aim:wpaimx:2616 Creation-Date: 2026-06-12 Note: Working paper AMSE 2026-16 Note: HAL hal-05666346 File-URL: https://hal.science/hal-05666346/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Revisiting the Theory of International Environmental Agreements with Heterogenous Players Abstract: We study an n-country pollution linear-quadratic differential game in which countries differ in their sensitivity to environmental damages while contributing to a common pollution stock. Such heterogeneity implies that countries value environmental quality differently and disagree on the desirable long-run environmental outcome. Consistently with the rising literature on carbon dioxide removal (CDR), we also allow for (optimal) negative emissions. We characterize the unique linear Markov-perfect (MPE) equilibrium and compare it to a centralized benchmark that maximizes aggregate welfare. We show that the inefficient steady-state pollution level at the MPE depends systematically on the distribution of damage sensitivities: intriguingly, holding average damages constant, more evenly distributed damages lead to more long-run pollution. Optimal negative emissions arise when the distribution of damage sensitives is asymmetric enough. We next show, among others, that while polarized damages reduce equilibrium pollution, they do generate distributional tensions. We therefore suggest a mechanism combining Pigouvian taxation with lump-sum transfers that can found an International Environment Agreement redistributing gains and implementing the first-best allocation despite divergent incentives. Author-Name: Raouf Boucekkine Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Author-Name: Weihua Ruan Author-Workplace-Name: Purdue University [West Lafayette] Author-Name: Benteng Zou Author-Workplace-Name: Université du Luxembourg = University of Luxembourg = Universität Luxemburg Classification-JEL: C62; C71; F53; H23; Q53 Keywords: Differential games; Asymmetric players; International Envionmental agreements; Transboundary pollution Number: 2615 Handle: RePEc:aim:wpaimx:2615 Creation-Date: 2026-06-09 Note: Working paper AMSE 2026-15 Note: HAL hal-05666302 File-URL: https://hal.science/hal-05666302/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: The Equilibrium Effects of Urban Air Quality Policies: Evidence from the Grand Paris Low-Emission Zone Abstract: Urban low-emission zones (LEZs) are increasingly used to reduce transportrelated air pollution, yet little is known about their long-run general equilibrium effects on the urban spatial structure and their implications in term of pollution exposure. To explore this question, we develop a quantitative spatial equilibrium model with endogenous commuting, transport mode choice and air pollution generated by transport, housing and firms activity. Pollution dispersion is described by an advection-diffusion equation accounting for atmospheric diffusion, deposition, and wind. We apply the model to the Grand Paris Low-Emission Zone and evaluate a long-run counterfactual in which internal combustion engine vehicles are banned from commuting within or through the regulated area. The results show that the policy substantially reduces car use and transport-related emissions. However, endogenous relocation by workers and firms partly offsets environmental gains by shifting economic activity and commuting flows toward more car-dependent peripheral areas, while simultaneously attenuating welfare losses. As a result, partial-equilibrium approaches that abstract from spatial reorganization tend to overestimate both the environmental benefits and welfare costs of the LEZ policy. Author-Name: Eva Gossiaux Author-Workplace-Name: Paris School of Economics Author-Name: Mohamed Bahlali Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: R13; Q53; R41; Q52 Keywords: General equilibrium effects; Low-emission zones; Air pollution; Transport policies; Quantitative spatial equilibrium Number: 2614 Handle: RePEc:aim:wpaimx:2614 Creation-Date: 2026-05-31 Note: Working paper AMSE 2026-14 Note: HAL hal-05642368 File-URL: https://hal.science/hal-05642368/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: A Unified Theory of Institutional Dynamics Abstract: We develop a unified dynamic game-theoretic theory of institutional change that delivers three common equilibrium outcomes as limiting cases: Lipsetian transition to democracy, transition through popular revolution, and permanent autocracy. An impulse-control framework captures both the citizens’ revolutionary option and the elites’ strategic choice of voluntary democratisation, with human capital as the unique endogenousstate and resource windfalls as an exogenous contributor to production and exports. The framework allows us to (1) characterise a reformation frontier, a state-feedbacklocus of minimal concessions that keeps the regime marginally stable as human capital evolves, and (2) identify conditions under which voluntary handover strictly dominates revolution or the status quo, providing a formal stopping rule for elites. We then confront the most distinctive part of the theory, the reformation-frontier mechanism, with data on a panel of 223 autocratic spells between 1970 and 2024. Two empirical signatures of the mechanism are present in the data: the within-spell adjustment of concessions saturates as human capital accumulates, and a cluster of long-lived high-polyarchy autocracies persists on the back of rent revenues. The joint configuration is consistent with our theoryand inconsistent with thin modernisation, rentier-curse, and state-capacity alternatives. Author-Name: Raouf Boucekkine Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Author-Name: Rodolphe Desbordes Author-Workplace-Name: SKEMA Business School [Lille] Author-Name: Weihua Ruan Author-Workplace-Name: Purdue University [West Lafayette] Author-Name: Benteng Zou Author-Workplace-Name: Université du Luxembourg = University of Luxembourg = Universität Luxemburg Classification-JEL: D72; D74; C61; C73 Keywords: Dynamic games; Reformation frontier; Redistribution; Education; Political transition Number: 2613 Handle: RePEc:aim:wpaimx:2613 Creation-Date: 2026-05-20 Note: Working paper AMSE 2026-13 Note: HAL hal-05642332 File-URL: https://hal.science/hal-05642332/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Beyond Fundamentals: Crashes and Bubbles in Global Oil Prices from a FIMARX model Abstract: This paper studies whether large swings in global crude oil prices reflect observable fundamentals alone or also embody forward-looking speculative dynamics. We develop a stylised asset-pricing model in which fundamentalists and sentimentdriven speculators coexist, which motivates a two-component equilibrium price: a backward-looking fundamental part and a forward-looking speculative part. Longmemory in the dividend process further motivates the use of fractional filtering. The theoretical model motivates our empirical specification: we combine fractional filtering with a mixed causal-noncausal autoregressive model to distinguish persistent movements from expectation-driven price dynamics in the oil prices, allowing speculative pressures to be two-sided and generate both upward bubble-like episodes and downward crash-like dislocations. We find that, even conditional on a rich set of oil-market, macro-financial, and geopolitical determinants, crude oil prices retain a forward-looking component. The results suggest that major oil-price fluctuations are shaped not only by fundamentals, but also by expectation-driven forces that amplify boom-bust dynamics. Author-Name: Gilles Dufrénot Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Author-Name: Céline Gimet Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: C22; G12; F51; Q41 Keywords: Overpricing; Crashes; Noncausal models; Long-memory; Oil prices Number: 2612 Handle: RePEc:aim:wpaimx:2612 Creation-Date: 2026-01-01 Note: Working paper AMSE 2026-12 Note: HAL hal-05623158 File-URL: https://hal.science/hal-05623158/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Sleeping Newcomb Abstract: I study games with self-locating uncertainty in which an agent at a single information set is uncertain of his position evenwithina given information set of a given play of the game. In such games, there is an analogy to be drawn with Newcomb’s problem: in bothsettings, locally rational (thirder) reasoning and globally optimal (planning) reasoning can prescribe different strategies. I call this aNewcomb tension, and present a representation theorem: a Bayesian with commitment power and an uncommitted agent holding incorrect ‘one-boxer’ beliefs are behaviourally equivalent. In the single-agent case, randomisation always resolves the tension but in multi-agent games, in which planning and interim social weights diverge under some conditions, a multi-agent Newcomb tension can survive this randomisation resolution with an asymmetric awakening structure across agents. I consider the implications of this for the duplicating Sleeping Beauty problem, and a duplicating variant of the absent-minded driver. Author-Name: John W. E. Cremin Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: C72; D71; D81; D83 Keywords: Sleeping Beauty Problem; Newcomb’s Problem; Self-Locating/Indexical Uncertainty; Imperfect Recall; Absent-Minded Driver Number: 2611 Handle: RePEc:aim:wpaimx:2611 Creation-Date: 2026-04-04 Note: Working paper AMSE 2026-11 Note: HAL hal-05594456 File-URL: https://hal.science/hal-05594456/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: A Stochastic Growth Model of a Poorly Developed Country with Natural Disasters Abstract: This paper proposes a dynamic model in which natural disasters affect the accumulation of private wealth, public spending, and output in an economy that is intended to capture salient features of developing countries. The central object of the analysis is the stationary distribution of key macroeconomic variables that emerges in the presence of recurrent, stochastic disasters. Within this framework, we derive analytic characterizations of the stationary distributions of private wealth, government spending, and GDP, and study how their shapes and tails depend on both disaster risk and institutional parameters. Natural disasters affect the economy via two channels. First, the effects on production are transmitted through a demand channel by altering the consumption-savings trade-off of households and thus the proportion of capital that can be invested in capital accumulation. Second, natural disaster shocks also activate a supply channel: they destroy capital and alter the way in which public spending influences total factor productivity. The stationary distributions of capital stock and public expenditure exhibit unusual characteristics such as Pareto laws and upper Gamma distributions. Our stylized model describes key mechanisms in developing countries and allows us to investigate the factors that enhance economic resilience to shocks, as well as those that may render their effects persistent. Author-Name: Gilles Dufrénot Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Author-Name: Edem Egnikpo Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: O11; Q54; E32; O43 Keywords: Stochastic growth; Public spending; Developing countries; Natural disasters Number: 2610 Handle: RePEc:aim:wpaimx:2610 Creation-Date: 2026-03-31 Note: Working paper AMSE 2026-10 Note: HAL hal-05594450 File-URL: https://hal.science/hal-05594450/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Convergence Rates for the Alternating Minimization Algorithm in Structured Nonsmooth and Nonconvex Optimization Abstract: This paper is devoted to developing the alternating minimization algorithm for problems of structured nonconvex optimization proposed by Attouch, Bolt´e, Redont, and Soubeyran in 2010. Our main result provides significant improvements of the convergence rate of the algorithm, especially under the low exponent PolyakLojasiewicz-Kurdyka condition when we establish either finite termination of this algorithm or its superlinear convergence rate instead of the previously known linear convergence. We also investigate the PLK exponent calculus and discuss applications to noncooperative games and behavioralscience. Author-Name: Glaydston C. Bento Author-Workplace-Name: Federal University of Goiás Author-Name: Boris S. Mordukhovich Author-Workplace-Name: Wayne State University [Detroit] Author-Name: Tiago S. Mota Author-Workplace-Name: Federal University of Goiás Author-Name: Antoine Soubeyran Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Keywords: Polyak- Lojasiewicz-Kurdyka conditions; Convergence rates; Noncooperative games; Alternating minimization algorithm; Nonsmooth optimization Number: 2609 Handle: RePEc:aim:wpaimx:2609 Creation-Date: 2026-01-30 Note: Working paper AMSE 2026-09 Note: HAL hal-05551606 File-URL: https://hal.science/hal-05551606/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: A Constructive Method to Maximize Entropy under Marginal Constraints Abstract: We study the problem of maximizing Rényi entropy of order $2$ (equivalently, minimizing the index of coincidence) over the set of joint distributions with prescribed marginals. A closed-form optimizer is known under a feasibility condition on the marginals; we show that this condition is highly restrictive. We then provide an explicit construction of an optimal coupling for arbitrary marginals. Our approach characterizes the optimizer's structure and yields an iterative algorithm that terminates in finite time, returning an exact solution after at most $p-1$ updates, where $p$ is the number of rows. Author-Name: Pierre Jean-Claude Robert Bertrand Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Keywords: Entropy maximization; Index of coincidence minimization; Coupling; Marginal constraints Number: 2608 Handle: RePEc:aim:wpaimx:2608 Creation-Date: 2026-03-02 Note: Working paper AMSE 2026-08 Note: HAL hal-05457049 File-URL: https://hal.science/hal-05457049/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Gender Differences in Learning about a Spouse’s Health: Field and Experimental Evidence Abstract: Using field data from an insurtech firm and a survey experiment, this paper studies health belief formation within couples. We document a strong gender asymmetry: Women increase critical illness insurance purchases for their husbands after negative health signals of COVID-19, hospital visits, and unhealthy lifestyles but do not adjust coverage for themselves, while men do not respond to either. Experimental evidence reveals pervasive health overconfidence and shows that women update on husbands’ negative health information but not their own, whereas men update neither. The findings highlight gendered belief updating and the importance of household decision-makers in financial choices. Author-Name: Ruo Jia Author-Workplace-Name: Peking University [Beijing] Author-Name: Jiawei Mo Author-Workplace-Name: Peking University [Beijing] Author-Name: Chang Zhang Author-Workplace-Name: Peking University [Beijing] Author-Name: Jiakun Zheng Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: G41; G52; I13 Keywords: Health overconfidence; Motivated beliefs; Gender differences; Insurance Number: 2607 Handle: RePEc:aim:wpaimx:2607 Creation-Date: 2026-02-24 Note: Working paper AMSE 2026-07 Note: HAL hal-05551484 File-URL: https://hal.science/hal-05551484/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Marital Rights, Education, and Labor Supply: Evidence from a Natural Experiment in France Abstract: This paper studies whether expanding women’s decision-making authority within marriage affects female labor supply and girls’ human capital investment. We exploit a major reform of French marital law in 1966, which reallocated control over labor and financial decisions from husbands to wives while leaving divorce institutions unchanged. Using census and family survey data, we implement two complementary empirical strategies. First, exploiting the discontinuity in access to the new marital regime by date of marriage, we show that women married under the new regime are 7 percentage points more likely to be employed more than thirty years later, after childrearing constraints have largely passed. Second, using cohort- and gender-based exposure to the reform, we find that girls who are at key educational decision ages when the reform is announced complete more schooling and are 13 percent more likely to obtain a baccalauréat or a higher-education degree. These education gains translate into higher employment rates and access to higher-skilled occupations in adulthood. Author-Name: Timothée Demont Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Author-Name: Roberta Ziparo Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: D13; J22; J24; K36; N3 Keywords: Gender; Education; Labor supply; Marriage law; Intra-household decision making Number: 2606 Handle: RePEc:aim:wpaimx:2606 Creation-Date: 2026-02-12 Note: Working paper AMSE 2026-06 Note: HAL hal-05515004 File-URL: https://hal.science/hal-05515004/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Strategic Communication of Economic Opportunities with Externalities Abstract: A subset of economic agents in a society is aware of the existence of an economic opportunity, and compete to exploit the opportunity. We study incentives to communicate about the existence of this economic opportunity when the exploitation of the opportunity by the winner generates externalities to other agents. We characterize the equilibria of the communication game and identify conditions under which more externalities generate more communication. Author-Name: Mohamed Belhaj Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Author-Name: Frédéric Deroïan Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Author-Name: Mathieu Faure Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: C72; D83; D85 Keywords: Opportunity; Strategic Communication; Externalities Number: 2605 Handle: RePEc:aim:wpaimx:2605 Creation-Date: 2026-02-09 Note: Working paper AMSE 2026-05 Note: HAL hal-05504606 File-URL: https://hal.science/hal-05504606/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: On the occupation measure of evolution models with vanishing mutations Abstract: We study the almost sure convergence of the occupation measure of evolution models where mutation rates decrease over time. We show that if the mutation parameter vanishes at a controlled rate, then the empirical occupation measure converges almost surely to a specific invariant distribution of a limiting Markov chain. Our results are obtained through the analysis of a larger class of time-inhomogeneous Markov chains with finite states pace, where the control on the mutation parameter is explained by the energy barrier of the limit process. Additionally, we derive an explicit L1 convergence rate, explained through the tree-optimality gap, that may be of independent interest. Author-Name: Michel Benaïm Author-Workplace-Name: Institut de Mathématiques Author-Name: Mario Bravo Author-Workplace-Name: Facultad de Administración y Economía [Santiago de Chile] Author-Name: Mathieu Faure Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Keywords: Evolution models; Inhomogeneous Markov chain; Occupation measure; Energy barrier Number: 2604 Handle: RePEc:aim:wpaimx:2604 Creation-Date: 2026-02-01 Note: Working paper AMSE 2026-04 Note: HAL hal-05504600 File-URL: https://hal.science/hal-05504600/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Changing Bodies Changes Minds-and Behavior? An Economists Guide to Embodiment Interventions Abstract: This review examines how virtual embodiment interventions can inform economic research on inequality across social groups. These interventions, widely used in psychology and related disciplines, consist of using virtual reality to embody individuals in virtual bodies whose appearance can be experimentally manipulated. By varying key characteristics such as skin-tone, gender, or age, researchers caninduce the illusion of inhabiting the body of an outgroup member. I synthesize existing research on outgroup embodiment and provide both a practical guide to designing embodiment interventions and a critical assessment of the methodological trade-offs involved in their implementation. In addition, I discuss how combining embodimentinterventions with tools from experimental economics can serve two purposes: first, to advance research on social inequality by introducing new methods to study its socio-cognitive foundations; and second, to address open questions in the embodiment literature by testing whether “changing bodies” can change not only minds but also behavior. Author-Name: Nina Rapoport Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: C91; D91; J16 Keywords: Discrimination; Inequality; Prejudice; Identity; Virtual reality; Experimental economics Number: 2603 Handle: RePEc:aim:wpaimx:2603 Creation-Date: 2026-02-11 Note: Working paper AMSE 2026-03 Note: HAL hal-05504559 File-URL: https://hal.science/hal-05504559/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Decision Rules in Choice Under Risk Abstract: We study choice among lotteries in which the decision maker chooses from a small library of decision rules. At each menu, the applied rule must make the realized choice a strict improvement under a dominance benchmark on perceived lotteries. We characterize the maximal Herfindahl-Hirschman concentration of rule shares over all locally admissible assignments, and diagnostics that distinguish rules that unify behavior across many menus from rules that mainly act as substitutes. We provide a MIQP formulation, a scalable heuristic, and a finite-sample permutation test of excess concentration relative to a menu-independent random-choice benchmark. Applied to the CPC18 dataset (N= 686 subjects, each making 500-700 repeated binary lottery choices), the mean rule concentration is 0.545, and 64.1% of subjects show excess rule concentration, rejecting menu-independent random choice at the 1% level. Concentration gains are primarily driven by modal-payoff focusing, salience-thinking, and regret-based comparisons. Author-Name: Avner Seror Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Classification-JEL: D91; D81; C44 Keywords: Behavioral Economics; Decision Theory; Revealed Preference Number: 2602 Handle: RePEc:aim:wpaimx:2602 Creation-Date: 2026-01-01 Note: Working paper AMSE 2026-02 Note: HAL hal-05483011 File-URL: https://hal.science/hal-05483011/document File-Format: application/pdf File-Restriction: no Template-Type: ReDIF-Paper 1.0 Title: Faith-Based Platforms Abstract: We develop a new model of faith-based organizations (FBOs) as multi-sided platforms. Faithbased platforms (FBPs) offer two types of services. The first is a religious service that includes providing a moral narrative, giving guidance and counselling, and proposing access to the divine through prayer, meditation or rituals. The second is a networking service that allows members to connect with members who come for the religious service. By offeringboth types of service, FBPs benefit from the spill-over effect of the religious service, whichhelps to screen for trustworthy network members. FBPs are more profitable than organizations that only offer areligious service, often even per capita, and are generally larger in size. The optimal community size depends on the type of interactions the FBP fosters and how much it invests in the quality of the religious service. This can explain the diversity of FBOs that continue to thrive despite secular competition and some recent phenomena that cannot be fully explained by existing models of FBOs, such as the growth of religion in some urban settings and the emergence of religious communities that have grown very large without sacrificing high profits per member. Author-Name: Emmanuelle Auriol Author-Workplace-Name: Toulouse School of Economics Author-Name: Amma Panin Author-Workplace-Name: Université Catholique de Louvain = Catholic University of Louvain Author-Name: Eva Raiber Author-Workplace-Name: Aix Marseille Univ, CNRS, AMSE, Marseille, France Author-Name: Paul Seabright Author-Workplace-Name: Toulouse School of Economics Classification-JEL: Z12; L14 Keywords: Religion; Faith-based organisations; Platforms Number: 2601 Handle: RePEc:aim:wpaimx:2601 Creation-Date: 2026-01-12 Note: Working paper AMSE 2026-01 Note: HAL hal-05464746 File-URL: https://hal.science/hal-05464746/document File-Format: application/pdf File-Restriction: no