Background: The average ethanol content of the beer sold in the US is a key factor in determining the per capita consumption of ethanol, the standard measure of alcohol use in aggregate-level research. To address the lack of empirically based estimates of beer ethanol content, we have calculated national estimates for the years 1988 to 2001 and state-specific estimates for 1993 to 2001.
Methods: These estimates are based on the ethanol content by volume of leading brands in each year, the national market share of each leading brand by type, and state-specific market shares of each beer type.
Results: The national mean ethanol content of beer was higher than the 4.5% figure typically used, ranging from 4.58% in 1993 to 4.75% in 1996. State-specific mean ethanol content estimates were also found to vary by state and over time. Application of mean ethanol content estimates to the per capita consumption of beer led to higher consumption estimates than those with the 4.5% conversion. For example, in 2000, the national estimate indicates that nearly 10 more drinks (containing 0.6 oz of ethanol) were consumed per person aged 14 years and older during that year.
Conclusions: This may indicate that a larger than previously estimated share of the alcohol consumed in the US is in the form of beer. However, the results also indicate that empirically based estimates of wine and spirits mean that ethanol content may modify their consumption estimates as well.