drinks: No significant correlation between caffeine use and hangover severity has been found. Epidemiology Hangovers occur commonly. A 1990 study of students at a rural New England university found that 25% had experienced a hangover in the previous week and 29% reported losing school time for hangover recovery. Fifteen percent of men and women who have consumed alcohol experience hangovers at least monthly and 10% of British men reported hangover-related problems at work at least monthly. An estimated 9.23% (11.6 million workers) of the U.S. labor force work with a hangover. About 23% of drinkers do not report any hangover after drinking to intoxication. Society and culture A somewhat dated French idiomatic expression for hangover is "mal aux cheveux", literally "sore hair" (or "[even] my hair hurts"). Some terms for 'hangover' are derived from names for liquor, for example, in Chile a hangover is known as a caña from a Spanish slang term for a glass of beer. Similar is the Irish 'brown bottle flu' derived from the type of bottle common to beer. Alcohol hangover has considerable economic consequences. A British study found that alcohol use accounted for 3.3 billion (USD) in lost wages each year, as a result of work missed because of hangovers. In Canada 1.4 billion (USD) is lost each year because of decreased occupational productivity caused by hangover-like symptoms. In Finland, a country with a population of 5 million persons, over 1 million workdays are lost each year because of hangovers. The average annual opportunity cost due to hangovers are estimated as 2000 (USD) per working adult. The socioeconomic implications of an alcohol hangover include workplace absenteeism, impaired job performance, reduced productivity and poor academic achievement. Potentially dangerous daily activities such as driving a car or operating heavy machinery are also negatively influenced. In mid-2017, it was reported that one company in the UK allows sick days when hung over. As of 2019, South Korea's 'hangover-cure product' market, which comes in various formulations such as beverages, pills, and jelly, is a 250 billion won (US$213 million) industry. Research Psychological research of alcohol hangover is growing rapidly. The Alcohol Hangover Research Group had its inaugural meeting in June 2010 as part of the Research Society on Alcoholism (RSA) 33rd Annual Scientific Meeting in San Antonio, Texas, USA. In 2012, Éduc'alcool, a Quebec-based non-profit organization that aims to educate the public on the responsible use of alcohol,