A new study from economists David Macpherson of Trinity University and William Even of Miami University estimates that California’s plan to hike its minimum wage incrementally to $15/hr. by 2022 will result in the loss of about 400,000 low-income jobs. Nearly half of those jobs would be in the accommodation, retail sales, and food service industries.

It’s another reminder that hiking the minimum wage hurts the very ones it’s supposed to help.

This breaks the first rule for policies to help the poor.

Some other recent studies of minimum wage increases in various parts of the country have estimated:

Seattle lost over 5,000 low-income jobs as the city’s $15/hr. minimum-wage phase-in went from $11/hr. to $13/hr. Workers on the remaining low-wage jobs saw their hours reduced, so that despite the higher hourly wages, they earned $125/mo. less than before.

St. Louis would lose about 1,000 low-income jobs by raising the city’s minimum wage to $11/hr., and the disemployed would be primarily working-age teenagers and young adults, disproportionately women, and the least educated.

Montgomery County, Maryland, would lose almost 47,000 jobs by raising the county minimum wage to $15/hr.

Finally, North Carolina could lose over 46,000 jobs by raising the state minimum wage to $10.10/hr. Or the state could aim for $15/hr. and lose over 367,000 jobs.