Photo Guibril Zerbo

GUIBRIL ZERBO

JEUNES DOCTEURS ET ATER

Research interests

  • arrow_right Gestion des risques et assurance
  • arrow_right Economie comportementale
  • arrow_right Economie du développement
  • arrow_right Economie appliquée
  • arrow_right Politiques publiques
  • arrow_right Confiance

Research group

    Comportements, Droits et Bien-être

HAL open science

Contact

2025-44

Exploring the link between insurance behavior and trust in markets

Olivier Renault, Guibril Zerbo

Abstract
We propose a model, called β-RDEu (Rank Dependent Expected Utility), that explains how distrust in an exchange relationship can lead to zero demand for a good or service, even when it is heavily subsidized. If an agent’s preferences, as estimated in a decontextualized environment (i.e., without distrust), are represented by a function V, then the β-RDEu function for a contract l is defined as βu(w_n) + (1 − β)V (l), and represents the agent’s preferences in a market environment where distrust may arise. The parameter β captures the agent’s level of distrust, and the wealth level wn represents an outcome excluded by the contractual relationship but considered plausible by a distrustful agent. We characterize the β-RDEu utility through a set of assumptions about preferences, and then apply the model to agricultural insurance demand. The main prediction is that agricultural insurance demand can be zero at any price if the agent is sufficiently distrustful, even though the contract provides positive net utility when assessed solely through the function V. We discuss the introduction of behavioral interventions aimed at either leveraging or reducing distrust to increase the adoption rate of agricultural insurance products. In particular, we propose a procedure to estimate the distribution of the β parameter within a population, in order to show how knowledge of this distribution can enhance the effectiveness of a subsidy.
Mot(s) clé(s)
Willingness to pay; Behavioral insurance; Distrust; Risk aversion; Zero probability distortions; Public policies
2024-30

Arbitrage entre assurance et auto-assurance contre les risques naturels

Guibril Zerbo

Abstract
This article studies the effect of preferences on an individual's optimal choice between insurance demand and self-insurance in a risk context and then in an ambiguous context. The innovative idea in this paper is to introduce ambiguity about the effectiveness of self-insurance to understand the nature of the relationship between insurance demand and self-insurance demand. We show that an increase in risk aversion increases the demand for insurance and decreases the demand for self-insurance. However, when risk is introduced on the effectiveness of self-insurance, we show that the individual still prefers self-insurance to market insurance. We also show that when ambiguity is introduced on the efficacy of self-insurance, the individual always prefers market insurance to self-insurance. Finally, we determine the conditions under which the individual's self-insurance effort is higher or lower under ambiguity than risk.
Mot(s) clé(s)
Natural risks, arbitration, insurance, self-insurance, efficacy, risk, ambiguity
2024-7

Disposition à payer pour l’assurance contre les risques naturels: une étude de terrain au Burkina Faso

Guibril Zerbo

Abstract
This article examines the determinants of willingness to pay (WTP) for flood insurance, focusing on the role of information and information sources. We use data from a September 2022 field survey of 593 individuals in urban Burkina Faso. We find that 71.3% of individuals are willing to spend money on insurance. But many individuals have a lower willingness to pay than the expected loss. This suggests that individuals would appreciate insurance cover, but do not have sufficient income to pay the insurance premium. We also find that being well informed about flood risk increases the likelihood of paying the expected loss for insurance. However, obtaining flood information from television increases WTP whereas radio does not. These results suggest the need to take information sources into account when developing effective communication policies against these risks. Another result is that recourse to the family and risk aversion reduce PAD. Finally, trust in insurers and ambiguity aversion increase individuals' chances of paying the expected loss for insurance.
Mot(s) clé(s)
Natural disasters, Flood risk; Insurance, Willingness to pay; Information
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