If there is a job out there that is worth $6 to an employer, and he can hire someone at $5/hr to do it, he makes a $1/hr profit, and has an incentive to hire the person.
Raise the minimum wage to $7/hr, and that employer would be taking a $1/hr loss by hiring someone to do it. Therefore, no one will be hired, and the job will go undone. Productivity suffers, and unemployment rises. Econ 101.
Now, in the real world there are complicating factors, and so the real effects of MODEST minimum wage increases are less clear. But rest assured, if the minimum wage were jacked up to some unreasonable number like $8/hr, there WOULD be an increase in unemployment. There are simply many, many people who do not have skills that make them worth that kind of money. And there are many jobs that are being done today that are not worth doing if you have to pay someone $8/hr to do it.
For example, we pay ‘Molly Maid’, a commercial company, to come and clean our house since we both work. They charge us $60US, and for that we get two people cleaning for about two and a half hours. That’s five hours of labor, plus call it an hour of transportation time for the cleaners, the cost of transportation, adn the costs of employment to the business.
If those cleaners made $10/hr, the direct labor cost would be $60. Add in employment costs (typically an additional 25% or so - management, employer’s contribution to unemployment insurance, etc). Now add maybe $10 in transportation cost, and $10 in cleaning supplies. The direct cost would be more like $100. Now, assume the company has a 30% markup on jobs. They would have to then charge us $130 for a cleaning.
Quite frankly, if home cleaning cost $130, we wouldn’t do it. We’d buckle down, and clean the house ourselves. So those two cleaners would lose five hours of work every two weeks.
That same equation applies all across the low-income spectrum. People who make low wages in a market where there is competition for labor because that is what they are worth. No more, no less. If you try and raise their wages by fiat, all you wind up doing is distorting the marketplace. Their hours are cut, they are forced to work longer hours in order to lower management overhead while other workers lose their jobs entirely. And, some jobs just stop being done. That would cause a loss of productivity, which in the long run might LOWER wages overall.