There is new evidence that raising the minimum wage pushes business owners to replace low-skilled workers with automation. And it shows that old, young, female and black low-skilled workers face the highest levels of unemployment after a minimum-wage increase.

Economists Grace Lordan of the London School of Economics and David Neumark of UC Irvine studied 35 years of government census data for their working paper, which was released in August, titled "People Versus Machines: The Impact of Minimum Wages on Automatable Jobs."