“This obsession with measuring and optimizing productivity is not new. In the thirteenth century, Venetian merchants carefully calculated the difference between the costs of the sailing voyages they underwrote and the revenues they ultimately earned from the goods sold, one of the first iterations of the Return on Investment calculation (ROI). This practice gave birth to the double bill accounting system and the “Equity - Assets = Liability” equation that’s still used today to determine the profitability of a business.”