A Measure of Sacrifice by Nick Szabo

Nick Szabo argues that the mechanical clock and the sandglass, which appeared together in late 13th and early 14th century Europe, enabled the time-rate wage and reshaped economic institutions. He writes that the era from the 14th to the 19th century saw the most rapid transformation of economic institutions in human history, during which physically coerced labor gave way to worker choice and slavery and serfdom disappeared. He describes Milan's 1288 bells and craft shops in the account of Bonvesin della Riva, and notes that precise time measurement let contracts verify an hour's or a day's labor.