Walmart's $446 billion of revenue last year was eye-popping, but its profit margins are far from fat--between 3% to 3.5%. If they cut that down by a percentage point--about what retailers like Costco and Macy's have been bringing in--that would give each Walmart employee about $2850 a year, which is substantial but far from life-changing. Further wage improvements would have to come out of the pockets of Walmart's extremely price conscious shoppers. Which might be difficult, given how many product categories Amazon is pushing into.

Earlier coverage here. Update from a reader:

Is Megan McArdle really as out of touch as she sounds? This is truly frightening in its upper-class cluelessness.