The average ethanol content of beer in the U.S. and individual states: estimates for use in aggregate consumption statistics.

OBJECTIVE: The purpose of this study is to describe the variation in the ethanol content of beer and specific categories of beer, and to illustrate the importance of accurate assessment of ethanol conversion factors for the calculation of apparent ethanol consumption from beer at the state and national levels in the U.S.
METHOD: Published sources of brand-level ethanol content, national brand share of beer categories and state beer category market shares are utilized to (1) estimate the mean ethanol content of each beer category in the U.S. for 1995 and 2000, (2) calculate per capita apparent consumption of ethanol from beer for 1995 and 2000 and for each state in 2000 and (3) describe trends in ethanol content for specific beer brands during the 1990s.
RESULTS: The mean ethanol content of beer in the U.S. is found to increase from 4.33% (by volume) in 1995 to 4.66% in 2000. Using these estimates, per capita ethanol from beer is found to increase from 1.386 gallons in 1995 to 1.468 gallons in 2000. Use of a constant ethanol conversion, however, indicates a decrease. Application of ethanol content estimates to state-level per capita consumption for 2000 changes the relative rankings of 28 states, compared to the use of a constant 4.5% ethanol conversion.
CONCLUSIONS: Improved ethanol conversion factor estimates are found to influence both time trends and the cross-sectional ranking of states, suggesting that analyses of both cross-sectional and time series aggregate ethanol consumption data that fail to consider variation in the ethanol content of beer may be biased.