Pennsylvania and Virginia recently passed legislation to increase their minimum wage to $15 per hour, closing the gap with Oregon ($15.55 as of July 1) and California ($17.90 in some places). In all, 34 states mandate a minimum wage higher than the federal minimum wage of $7.25 per hour. The potential economic detriments of a minimum wage — namely, job losses — are well known. But the trend toward higher and higher minimum wages ought to prompt us to reconsider their purpose. The standard assumption about progressivism is that it’s intrinsically good — after all, who would oppose progress? Progressivism...