title: Rising gasoline prices increase new motorcycle sales and fatalities.
abstract: BACKGROUND
  We examined whether sales of new motorcycles was a mechanism to explain the relationship between motorcycle fatalities and gasoline prices.
  
  
  METHODS
  The data came from the Motorcycle Industry Council, Energy Information Administration and Fatality Analysis Reporting System for 1984-2009. Autoregressive integrated moving average (ARIMA) regressions estimated the effect of inflation-adjusted gasoline price on motorcycle sales and logistic regressions estimated odds ratios (ORs) between new and old motorcycle fatalities when gasoline prices increase.
  
  
  RESULTS
  New motorcycle sales were positively correlated with gasoline prices (r = 0.78) and new motorcycle fatalities (r = 0.92). ARIMA analysis estimated that a US$1 increase in gasoline prices would result in 295,000 new motorcycle sales and, consequently, 233 new motorcycle fatalities. Compared to crashes on older motorcycle models, those on new motorcycles were more likely to be young riders, occur in the afternoon, in clear weather, with a large engine displacement, and without alcohol involvement. Riders on new motorcycles were more likely to be in fatal crashes relative to older motorcycles (OR 1.14, 95 % confidence interval (CI) 1.02-1.28) when gasoline prices increase.
  
  
  CONCLUSIONS
  Our findings suggest that, in response to increasing gasoline prices, people tend to purchase new motorcycles, and this is accompanied with significantly increased crash risk. There are several policy mechanisms that can be used to lower the risk of motorcycle crash injuries through the mechanism of gas prices and motorcycle sales such as raising awareness of motorcycling risks, enhancing licensing and testing requirements, limiting motorcycle power-to-weight ratios for inexperienced riders, and developing mandatory training programs for new riders.
authors.affiliation: School of Medicine, Duke University, 201 Trent Dr, Durham, NC, 27710, USA.
authors.forename: He
authors.initials: H
authors.lastname: Zhu
authors.affiliation: College of Public Health, University of Nebraska Medical Center, 984350 Nebraska Medical Center, Omaha, NE, 68198-4350, USA. fernando.wilson@unmc.edu.
authors.forename: Fernando A
authors.identifier: http://orcid.org/0000-0002-8801-9026
authors.initials: FA
authors.lastname: Wilson
authors.affiliation: School of Public Health, City University of New York, 2180 Third Avenue, New York, NY, 10035, USA.
authors.forename: Jim P
authors.initials: JP
authors.lastname: Stimpson
authors.affiliation: Joseph M. Long Chair in Healthcare Management and Professor of Economics, Eberhardt School of Business, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, 3601 Pacific Avenue, Stockton, CA, 95211, USA.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Hilsenrath
keywords: Mortality; Motorcycles; Traffic accidents