Equal sacrifice theory maintains that all members and sectors of society should make equal sacrifice for the common good. This theory has been critical to political economy since the 18th century, particularly as it pertains to taxation. Yet the idea is broader than the economics of taxation: Both the Old and the New Testament of the Judeo-Christian Bible emphasize charitable personal sacrifice—the Hebraic requirement of tithing and Jesus's parable of the poor widow giving up two coins to the collective pot; the idea even appears in 20th-century American poetry—in Robert Frost's “In Equal Sacrifice.” In economics, equal sacrifice theory developed from historically and ethnically diverse strains: the 18th-century Frenchman Jean-Baptiste Say; the Swiss Jean-Jacques Rousseau; and the British William Gladstone, John Stuart Mill, and F. ...