Give all citizens a modest, yet unconditional income, and let them top it up at will with income from other sources.

This exceedingly simple idea has a surprisingly diverse pedigree. In the course of the last two centuries, it has been independently thought up under a variety of names—“territorial dividend” and “state bonus,” for example, “demogrant” and “citizen’s wage,” “universal benefit” and “basic income”—in most cases without