Publications

(PhD 2014 – 2017, PhD defense in september 2017)

Articles in international peer-reviewed journals

(FORTHCOMING) The effects of short selling and borrowing on traders’ expectations and market outcomes (with Éric Guerci, Nobuyuki Hanaki and Charles Noussair), Journal of Economic dynamics and control [CNRS cat. 1/HCERES A]

Abstract: This paper studies the effect of allowing borrowing and short selling on market prices and traders’ forecasts in an experimental asset market. There are four treatments, organized in a 2×2 design based on whether or not margin buying is allowed, and whether short selling is permitted or not. We observe that borrowing and short selling do not have significant effects on prices and forecasts due to extensive within-treatment heterogeneity. Beliefs are based on past prices of the current and previous markets, regardless of borrowing or short selling possibilities. Traders who have greater cognitive abilities tend to make more use of short selling and borrowing. A number of relationships regarding traders’ types, cognitive sophistication, and earnings observed in earlier experimental studies in which borrowing and short selling are not possible, generalize to markets with borrowing and short sales.

(2017) Une nouvelle approche expérimentale pour tester les modeles quantiques de l’erreur de conjonction (with Thomas Boyer-Kassem and Éric Guerci), la Revue Économique, 5, 16-31 (HCERES: A, CNRS: 2).

Résumé: La théorie classique des probabilités requiert que la probabilité de la conjonction de deux événements soit inférieure a la probabilité d’un des événements seul. Or les sujets ne jugent empiriquement pas toujours ainsi : c’est la traditionnelle erreur de conjonction. L’une des explications actuellement prometteuses de ce paradoxe repose sur des modèles dits « quantiques », développés a partir des outils mathématiques de la mécanique quantique. Mais ces modèles sont-ils empiriquement adéquats ? Quelles versions de ces modèles peuvent être employées ? En particulier, les versions les plus simples, dites non-dégénérées, peuvent-elles être suffisantes ? Nous proposons ici un protocole expérimental original pour tester
en laboratoire les modèles quantiques de l’erreur de conjonction. Les résultats obtenus suggèrent que les modèles non-dégénérés ne sont pas empiriquement adéquats, et que la recherche future concernant les modèles quantiques devrait s’orienter vers les modèles dégénérés.

(2016) quantum-like models cannot account for the conjunction fallacy (with Thomas Boyer-Kassem and Éric Guerci), Theory and Decision, 81(4), 479-510 [doi] (HCERES: A, CNRS: 2)

Abstract: Human agents happen to judge that a conjunction of two terms is more probable than one of the terms, in contradiction with the rules of classical probabilities—this is the conjunction fallacy. One of the most discussed accounts of this fallacy is currently the quantum-like explanation, which relies on models exploiting the mathematics of quantum mechanics. The aim of this paper is to investigate the empirical adequacy of major quantum-like models which represent beliefs with quantum states. We first argue that they can be tested in three different ways, in a question order effect configuration which is different from the traditional conjunction fallacy experiment. We then carry out our proposed experiment, with varied methodologies from experimental economics. The experimental results we get are at odds with the predictions of the quantum-like models. This strongly suggests that this quantum-like account of the conjunction fallacy fails. Future possible research paths are discussed.

 

(2016) testing quantum-like models of judgment for question order effect (with Thomas Boyer-Kassem and Éric Guerci), Mathematical Social Sciences, 80 : 33-46 [doi] (HCERES: A, CNRS: 2) .

Abstract: Lately, so-called « quantum » models, based on parts of the mathematics of quantum mechanics, have been developed in decision theory and cognitive sciences to account for seemingly irrational or paradoxical human judgments. We consider here some such quantum-like models that address question order effects, i.e. cases in which given answers depend on the order of presentation of the questions. Models of various dimensionalities could be used; can the simplest ones be empirically adequate? From the quantum law of reciprocity, we derive new empirical predictions that we call the Grand Reciprocity equations, that must be satisfied by several existing quantum-like models, in their non-degenerate versions. Using substantial existing data sets, we show that these non-degenerate versions fail the GR test in most cases, which means that, if quantum-like models of the kind considered here are to work, it can only be in their degenerate versions. However, we suggest that the route of degenerate models is not necessarily an easy one, and we argue for more research on the empirical adequacy of degenerate quantum-like models in general.

Other publications

(2019) « Green Money » (English Book Review of Climat un défi pour la finance by Ducret and Scolan 2016), in Books & ideas https://booksandideas.net/Green-Money.html

(2018) Too fast, Too furious ? Une réflexion historique et contemporaine sur l’emballement des marchés financiers (with Nathalie Oriol) , 1024 – Bulletin de la société informatique de France, 12 : 47-65 [doi]

(2018)  « La monnaie verte » (Recension/Book Review of Climat un défi pour la finance by Ducret and Scolan 2016), in La Vie des Idées http://www.laviedesidees.fr/La-monnaie-verte.html

Working or submitted papers

On discrimination in health insurance (with Thomas Boyer-Kassem) Revise & Resubmit, Round 1, in Social Choice and Welfare [CNRS cat. 1/HCERES A]

A Dual Process in Memory: How to make an evaluation from complex and complete information? An experimental study (with Ismaël Rafaï, Éric Guerci, Ariane Lambert-Mogiliansky and Fabien Mathy) Revise & Resubmit, Round 2, in la Revue Économique [CNRS cat. 2/HCERES A]

Work in progress

« Financial Market Professionals’ Higher Order Risk Attitudes » (with Anna Bottasso, Éric Guerci, Nobuyuki Hanaki and Charles Noussair).

« Financial Market Professionals’ Under-investment and Under-diversification » (with Anna Bottasso, Ido Erev, Éric Guerci and Nobuyuki Hanaki).

« Investors, forecasts and price dynamics of companies complying with environmental rules (SRI), a laboratory experiment » (with Olga Tatarnikova, Patrick Sentis and Marc Willinger)

« SRI investments » (with Dimitri Dubois, Adrien Nguyen-Huu and Marc Willinger).

« Testing Boundaries of Applicability of Quantum Probabilistic Formalism to Modeling of Cognition in an experiment » (with Irina Basieva , Jacob Denolf, Eric Guerci, Andrei Khrennikov and Ismaël Rafaï).

Online Appendix

Instructions borrowing and short selling