FORTUNE -- Worried about buying a $70 pair of sneakers that say "Made in China" this back-to-school season because you'd rather spend your dollars on "Made in U.S.A." products instead? Worry not, according to a new study. More than half the amount you spend on products made in China actually stays here -- going to American companies, workers, marketers, retailers, and transport providers. The amount is least 55 cents per each $1 spent, says a report from the Federal Reserve Bank of San Francisco. So for that $70 pair of sneakers, $38.50 of it boosts bottom lines here in the U.S. And despite what you may conclude from shopping at Wal-Mart (WMT) or other large stores -- or hearing big, scary figures about the trade deficit with China -- imports from China make up just a very small portion of our total economy: just 2.5% of gross domestic product in 2010. Overall, products from around the world accounted for only 16% of our GDP last year. "The vast majori