Today, Walmart announced a striking decision: The retail giant is going to give 500,000 of its workers a pay raise. Just like that. Walmart's minimum wage, from April onward, will be $9 an hour, $1.75 more than the federal minimum wage. By next February, that $9 will rise to $10. There are lessons here for both left and right. First, this should show progressives that the government doesn't actually have to mandate a minimum wage hike for wages to go up.