Agree also with the other comment here that the minimum wage is a structural advantage for Costco against Walmart.
Walmart socialize their labor costs by pushing their employees on to government aid, eg food and healthcare.
US Government mandated minimize wage forces corporate welfare basket cases like Walmart to start carrying more of their own water.
People arguing against minimize wage carefully omit that corporate profits are at all time high while wages have stagnated for decades. Coincidence?