Henry Ford was onto something.

In 1914, the automaker began paying his factory workers $5 per day for eight hours of work on the assembly line. Although Ford had refined mass production to make it more efficient, he still needed employees to show up and stick around. The generous wage, equivalent to about $148 today, was meant to keep workers coming back.

A recent Wharton study measuring the effect of worker turnover on the quality of smartphones made in China proves what Ford probably realized more than 100 years earlier at his car plant in Michigan: A stable workforce is valuable, even in a factory setting where so much of the labor is unskilled.

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