The peasant's free time extended beyond officially sanctioned holidays. There is considerable evidence of what economists call the backward-bending supply curve

The peasant's free time extended beyond officially sanctioned holidays. There is considerable evidence of what economists call the backward-bending supply curve of labor -- the idea that when wages rise, workers supply less labor. During one period of unusually high wages (the late fourteenth century), many laborers refused to work "by the year or the half year or by any of the usual terms but only by the day." And they worked only as many days as were necessary to earn their customary income -- which in this case amounted to about 120 days a year, for a probable total of only 1,440 hours annually (this estimate assumes a 12-hour day because the days worked were probably during spring, summer and fall). A thirteenth-century estime finds that whole peasant families did not put in more than 150 days per year on their land. Manorial records from fourteenth-century England indicate an extremely short working year -- 175 days -- for servile laborers. Later evidence for farmer-miners, a group with control over their worktime, indicates they worked only 180 days a year.