1917 World War I There was a nationwide mobilization of labor to produce the necessary goods for war. And a study was conducted on the relationship between working hours and output in order to maximize production. In 2015 Economist John Pencavel discovered new information using data collected during this period. Output rises by the hour but at a decreasing rate. And, above a certain threshold, it is not sensitive to hourly changes. The Impact of a Workweek Reduction on Labor Productivity According to OECD statistics, countries with shorter working hours tend to have higher labor productivity. In Korea’s case, the hours are long and hence, productivity is low. However, despite the general consensus calling for reform of the long-hours culture prevalent in Korean society, concerns are also being raised over the negative impact a cutback in working hours would have on productivity. Then, how would productivity be affected? KDI analysed the impact of the standard 40-hour workweek, the most recently implemented policy to reduce working hours, on the labor productivity of 11,692 manufacturing establishments with 10 or more employees. The policy reduced the workweek from 44 hours to 40, and was gradually implemented across the country according to industry and size of establishment, from 2004 to 2011.