The idea of a living wage is an old dream, with origins in the work of thinkers as ideologically diverse as Adam Smith, St. Thomas Aquinas and Karl Marx. While its exact meaning is often left conveniently vague, Theodore Roosevelt offered a basic definition in a 1912 speech: A living wage should let workers “secure the elements of a normal standard of living,” including education, recreation, child care, a cushion for periods of sickness and savings for old age.

Roosevelt was making a moral claim, not just an economic one. He saw paying workers enough to meet these basic standards as a matter of justice.

More than a century later, millions of working Americans are still paid too little to afford the modest elements in Roosevelt’s vision. Such low wages are not inevitable; they reflect political and moral choices about what defines a “normal standard of living,” and who deserves to enjoy one.

Defining a meaningful living wage is a two-part challenge. There’s the moral imperative of framing a generous definition of […]