Coastal communities and beachfront property owners often respond to erosion byadding sand to restore local beaches. But beach nourishment alters shorelinedynamics, not only at the replenishment site but also in adjacent coastal regions,as natural coastal processes shift sand from one location to another. The result isthat "sucker" communities pay to build up their beaches, but that replenishmentalso helps protect the coastlines of "free rider" communities. The sucker-free ridersituation is an example of a classic problem studied in economics and gametheory frameworks.
Using model simulations of the dynamics of coastlines similar to those alongmuch of the U.S. East Coast, coupled with a model of locally economicallyoptimal nourishment decisions, Williams et al. find that interactions between theerosion processes and economic and physical feedbacks do tend to lead to thesucker-free rider situation. Large inequalities in property values can result,especially as the cost of sand for nourishment rises.
The results indicate that decentralized management of beach nourishment, inwhich individuals or communities make locally optimal decisions without takinginto account the effects on others may lead to a use of resources that is notoptimal over a wider area.
Source: Journal of Geophysical Research-Earth Surface, doi: 10.1002/jgrf.20066, Title: Coupled Economic-Coastline Modeling with Suckers and Free Riders Authors:Zachary C. Williams and Dylan E. McNamara: Center for Marine Science,University of North Carolina Wilmington, Wilmington, North Carolina, USA, andDepartment of Physics and Physical Oceanography, University of North CarolinaWilmington, Wilmington, North Carolina, USA; Martin D. Smith: Nicholas School of the Environment, Duke University, Durham,North Carolina, USA, and Department of Economics, Duke University, Durham,North Carolina, USA;A Brad. Murray: Nicholas School of the Environment, Duke University, Durham,North Carolina, USA, and Center for Nonlinear and Complex Systems, DukeUniversity, Durham, North Carolina, USA; Sathya Gopalakrishnan: Department of Agricultural, Environmental andDevelopment Economics, The Ohio State University, Columbus, Ohio, USA.