Aisha Salih*, Guillaume Bataille**

phd seminar

Aisha Salih*, Guillaume Bataille**

Climate change shocks and demand for religious insurance*
Managing predator-prey harvesting with prey-refuges**
Joint with
Eva Raiber*

MEGA Salle Carine Nourry

MEGA - Salle Carine Nourry

Maison de l'économie et de la gestion d'Aix
424 chemin du viaduc
13080 Aix-en-Provence

Tuesday, April 11 2023| 11:00am to 12:15pm

Camille Hainnaux: camille.hainnaux[at]
Daniela Horta Saenz: daniela.horta-saenz[at]
Jade Ponsard: jade.ponsard[at]
Nathan Vieira: nathan.vieira[at]


*This ongoing project explores the relationship between climate uncertainty in agrarian settings and the demand for “religious insurance”. We test how religiosity and religious participation respond to climate shocks caused by long-onset climate change. We exploit two main datasets: the World Bank's General Household Panel Survey in Nigeria, and the Standardized Precipitation Evapotranspiration Index which estimates drought probability and severity. As an additional proxy of religiosity, we use Night Lights data as a measure of adherence to Ramadan. We then investigate how this relationship interacts with formal insurance and other forms of risk sharing. This work contributes to the recent literature using quasi-exogenous methods and spatial econometrics to study religion.

**This study investigates the effectiveness of a prey-refuge policy in regulating harvesting activities within a predator-prey system. Building upon existing literature, I first derive a tractable model for the simultaneous exploitation of a predator-prey system, in which a constant proportion of the prey population is protected by the refuge. Assuming selective harvesting and competition among fisheries, I demonstrate the existence of a Feedback-Nash symmetric equilibrium in linear strategies. Next, given the trajectories of fisheries' harvests over time, I investigate the regulator's optimal choice of the proportion of protected prey in order to maximize the discounted sum of aggregate welfare. Using numerical simulations, I find that there exists a threshold for the share of protected prey that maximizes the aggregate welfare of both prey and predator fisheries. Protecting a small proportion of prey from predation benefits both the prey and predator stocks, as it increases the food availability for predators. However, as the proportion of protected prey becomes large enough, the predator's population decreases due to reduced access to prey, even if the prey stock remains large. Therefore, the aggregate welfare of the system may decrease with the size of the refuge. My findings suggest that protecting an appropriate proportion of prey from natural predation can increase the economic efficiency of the fishery in a second-best world, and non-market based instruments such as artificial reefs may be utilized for fisheries management.