“The problem is that a higher legal minimum wage is at odds with the prevailing supply of and demand for labor. If you set the minimum too high, you will get a shortage of jobs. Forbidding employers from paying $9 or $12 an hour means that many of their workers won’t get $13 or $15 an hour. They will get zero per hour, because those jobs will disappear.
Some businesses will reduce staffing or hours. Some will scrub expansions they had planned. Some will install machines to handle tasks previously assigned to humans. Some will shut down.”
Via The Costs of a $15 Minimum Wage @ RealClearPolitics