Last week, we learned that Wal-Mart was giving the lowest paid of its hourly employees a raise. In a blog post, Wal-Mart Chief Executive Officer Doug McMillon said that as of April, the company will pay a minimum of $9 an hour. That is $1.75 more than the federal minimum wage of $7.25, which has been unchanged for almost six years. Next February, Wal-Mart's lowest hourly rate will rise to $10. All told, about a half-million Wal-Mart workers in the U.S. will be affected.