Here's How We Made Business Insider's Hangover Index

We recently posted a map showing how hung over each state was after New Year's Eve, and a list of the most hungover cities. These rankings were based on a few indicators of heavy drinking activity. Here's how we compiled those rankings.

The BI Hangover Index is made up of four components:

Binge Drinking: This measures the percentage of adult respondents in each state or Metropolitan Statistical Area (MSA) to the CDC's 2010 Behavioral Risk Factor Surveillance System survey who answered yes to a question on binge drinking (defined as men having five or more drinks on one occasion, and women having four or more drinks on one occasion).

Bars per 100,000 residents: The number of bars in each state or MSA was found in the Census Bureau's 2011 County Business Patterns (NAICS code 722410), and this number was divided by the most recent Census estimates of each state's population from the American Community Survey.

Beer, Wine, and Liquor Stores per 100,000 residents: Similarly to bars, the number of Beer, Wine, and Liquor Stores in each state or MSA was found in the Census Bureau's 2011 County Business Patterns (NAICS code 445310), and this number was divided by the most recent Census estimates of each state's population from the American Community Survey.

Breweries per 100,000 residents: The number of breweries per capita in each state was taken from the Brewers Association's capita per brewery 2012 report. MSA level data was not available from the Brewers Association, so for the cities list, the number of breweries for the state in which the principal city of the MSA is located was used.

The state map uses data from each of the fifty states and Washington, D.C., and the city list is based on the 168 metropolitan areas and divisions included in the CDC Behavioral Risk Factors study. The states or cities were percentile ranked in each of the four categories, and the BI Hangover Index for each state or city is the average of the four rankings, giving a score with a theoretical range between 0 and 99 for each state or city. The state map (generated using QGIS) compares the Hangover Index scores for the states, with a darker blue indicating a higher score.