From the blog formerly known as Green, Inc (now known simply as the Crayola crayon):
An economist, an oceanographer and an expert in complex systems have just published a study posing a question: What happens if physical predictions about the erosive force of future storms are entwined with economic predictions of how coastal towns deal with the loss of their beaches?
Their models essentially yield this answer: If the cost of replacement sand increases as the supply decreases, richer communities will use up most of the sand. That will hold true whether or not the wealthier towns are more prone to erosion than those with lower property values.
If the communities with higher property values are on northern outcroppings of a cape, thus vulnerable to greater erosion, they will spare no effort, responding most aggressively to maintain their beaches. In so doing, they will use so much of the available reservoir of sand that the cost of sand will go up for everyone, write the authors of the study, which was published online Tuesday in the journal Geophysical Research Letters.
Poorer communities will tolerate more beach loss over time rather than pay the increased cost of replenishing the sand, which in the scientific lexicon is known as “nourishment.”
“Eventually, lower property-value towns reach a point at which nourishment becomes too expensive to justify,” write the authors, Dylan E. McNamara of the University of North Carolina at Wilmington’s Department of Physics and Physical Oceanography; A. Brad Murray of the Center for Nonlinear and Complex Systems at Duke’s Nicholas School for the Environment; and Martin D. Smith, an economist at the Nicholas School.
“Rising nourishment costs not only alter behaviors of low and high property-value towns,” the authors write, “but rising costs also intensify inequality in distribution of sand resources.”
If the town with lower property values is on the northern flank of that small cape, it will use more of the available sand than if it were less vulnerable. But it will slacken its efforts to control erosion sooner than a richer neighbor would. “Consequently, higher property-value towns, whether located along the northern or southern flank, use a higher proportion of the sand reservoir,” the study said. ...
“In the current management paradigm along much of the U.S. East Coast,” the authors write, “each town operates by considering what is best for itself without consideration of future nourishment in other towns.”
“Regional management strategies could alter the rate of resource depletion, perhaps allowing more time for development of new technologies that could make new sources of sand economically viable,” the authors suggest.
Sand is a normal good, no surprise there. The most interesting part is the magnitudes of the estimates. Unfortunately, you need money to get the PDF (I might be able to get it on my campus computer). Also, I seriously doubt the feasibility of regional management strategies. A better prediction is that rich beach communities will have sand and houses right behind the dunes. Less rich beach communities will be forced to adopt retreat strategies.
* ... (I heard this one on St. Patrick's day.) All three order a stout. After one sip a fly drops into all three glasses. The economist pushed the drink away and ordered another. The oceanographer fished the fly out of the glass and continued drinking. The expert in complex systems (isn't there a better name for a scientist who studies "complex systems"? It's like calling Marty Smith an expert in the allocation of scarce resources) also pulled the fly out of his glass and, holding it over the glass, shouted "spit it out you b******d, spit it out!"