Hazardous human-wildlife encounters, risk attitudes, and the value of shark nets for coastal recreation

Abstract

Shark incidents are rare and graphic events, and their consequences can influence the behavior of beach users, including bathers, to a great extent. These incidents can be thought of as a fearsome risk that may lead decision makers to overreact or respond with inaction. This paper examines the reaction of recreational beach users, including bathers, to changes in the risk of shark incidents. In addition to valuing recreational visits to Durban Beach, South Africa, we study the reaction of beach visitors to a hypothetical scenario in which protective shark nets, deployed in coastal waters to protect bathers, are to be removed. To examine potential heterogeneity of the treatment effect in a travel cost-contingent behavior model, we develop a semiparametric multivariate Poisson lognormal (MPLN) model to jointly analyze observed and stated visit counts. Results show that removing protective shark nets at Durban beach would decrease recreational visits by more than 20%. Applying the semiparametric MPLN model we further find that both the value of a recreational visit and the predicted change in visitation rates vary as a function of whether recreationists usually enter the water, whether they have heard of previous shark incidents, and their general risk attitude.