Apple CEO Tim Cook announced that starting next year, Apple will be bringing some of the production of its Mac computers back to the US. The sum of $100 million is slightly more than 1/100 of the company's profits last quarter, so the announcement was dismissed in some quarters as a publicity ploy. On the other hand, the relatively small size of the initial investment doesn't mean the company isn't taking the effort seriously. It's possible that it's an experiment, a small pilot program exploring whether the company can profitably and reliably make its products in the US. Labor costs make up a fairly small sliver of the cost of an Apple product. Still, according to Blake Johnson, a manufacturing and supply chain expert at Stanford University, Apple is not simply going to replace $2.50-an-hour labor in Shenzhen with $15-an-hour American workers. Instead, the plan is most likely to shift to more automated manufacturing, an approach that Johnson points out makes particular sense for Apple.