Who says the market on old books is in a downward spiral? Luca Pacioli wrote the definitive treatise Summa de Arithmetica, Geometrisa, Proportioni et Proportionalita and published it in Venice in 1494. On June 12, 2019, Christie’s put up one copy for auction. (The starting price was one million USD; it eventually sold for 1.2 million USD.) Experts estimate 120 copies of this book still exist. An image of a typical page, reproduced here, shows its type font is somewhat less readable than the modern accounting textbook. Summa de Arithmetica was widely read and used at the time. It contains real-life examples, […]