It is really very simple. Workers through their labor must produce enough revenue to pay their wage plus the other fixed and variable costs of operation. Consider that a worker at Wal- Mart with a $15 per hour wage must on average generate at least $15 of revenue just to pay their wage. Realistically most Wal -Mart workers aren’t that productive. Since labor and capital are interchangeable higher wages simply mean that it becomes more efficient to automate than pay higher wages. Watch for check out lines at Wal-Mart for an increasing number of self check out and fewer cashiers
It's already happened at my local Super Walmart. The first 6 regular registers were replaced last week with 4 self checkout ones. One live Walmart person assisting those using the 4.