What can and can't a $15 minimum wage do? That's the question answered by Mark Perry, an American Enterprise Institute scholar and University of Michigan-Flint economics professor.

Perry explains that the minimum wage requires employers to pay their employees a minimum of $15 an hour. That's it. That's all that proponents of the policy are calling for, but as Perry notes, there's a lot the law can't do, and that's where the problems occur.

For example, the policy "does not guarantee that a single new job will be created," Perry wrote. It also "cannot stop employers from reducing the number of weekly work hours assigned to employees at the new $15 an hour minimum wage."

Other things the policy can't do include stopping companies from bringing in robots or kiosks to take the place of low-skilled workers and keeping businesses from choosing to move to cities and states where the minimum wage is lower.

If you'd like to see the other things the minimum wage proposals can't do, read Perry's entire article.

Cities, like Seattle, Wash., that have implemented a $15 minimum wage have seen job losses and business closures. Fast-food restaurants like McDonald's have already started installing kiosks so cashiers will no longer be necessary.

Proponents of the policy claim that for every job that's lost, many more jobs will be helped. That's a pretty poor defense of the policy on it's own, but those being "helped" aren't being benefited the way proponents claim. Even if a person does keep her job and get the raise to $15 an hour, she might not make any more money — she could even earn less. That's because, as Perry notes in his article, employers can and will reduce benefits or hours for those making more money.

There are always consequences.

Ashe Schow is a commentary writer for the Washington Examiner.