This excerpt originally appeared in The Wall Street Journal on March 13, 2012.

Put yourself in the place of an employer and ask: If I must pay $8.50 an hour to whomever I hire, does it pay me to hire a person who is so unfortunate as to possess skills that would only allow him to contribute $5 an hour to my bottom line? Most employers would view hiring such a person as a losing economic proposition. Therefore the effect of minimum-wage legislation is to discriminate against the employment of low-skilled persons, who are for the most part young, and mostly minority young, people.