A University of Virginia study of consumer data finds that people in the path of a hurricane don’t closely follow official advice to stock up on bottled water. The study has implications for how well citizens and communities understand and prepare for natural disasters.

The study, a working paper by public policy professor Jay Shimshack at UVA’s Frank Batten School of Leadership and Public Policy, and colleagues at two California universities, explores bottled water sales before, during and after hurricanes. The team focused on bottled water because sales data is readily available, and local, state and federal guidelines state that bottled water is an essential emergency preparedness commodity.

Early results show that bottled water sales increase modestly, around five to 15 percent, in coastal areas as hurricanes approach. The researchers found sharper increases, up to 135 percent, in bottled water sales across affected communities after hurricane landfalls. Communities most likely to prepare ahead of time saw much smaller increases in sales after storms made landfall.

The researchers’ analysis concludes by examining market effects, including the impacts of hurricanes on product prices and sales composition. Prices did not change as storms approached, but increased modestly – about two percent on average – after storms made landfall.

To gain their results, Shimshack and his colleagues – Timothy Beatty of the University of California, Davis and Richard Volpe of California Polytechnic State University – matched extensive store-level scanner data from thousands of supermarkets, made available through the Nielsen Company, with National Weather Service tropical cyclone data from dozens of storms over several Atlantic hurricane seasons.

“The good news is that findings suggest household-level preparation may pay off, and private-sector supply chain responses to tropical cyclones tend to be rapid and effective,” Shimshack said. “The bad news is that public responses to outreach efforts often fall short of stated policy objectives. Preparedness and response behavior is not consistent with policy advice. Also, lower-income, less-educated and minority consumers appear less prepared and/or suffer greater damages.”

The researchers recommend that better and more targeted risk communication may be necessary.