“Whether you’re on the road or just cruising around town, your favorite McDonald’s menu items are never far away.” So boasts the McDonald’s Restaurant Locator, and a glance at a distribution map of franchises in the United States proves the point. Population centers burn brightly with the Golden Arches; even the sparsely populated Western states are adequately supplied by the nation’s 14,000-plus fleet of McDonald’s.

That reach is astounding, but not exceptional. Four out of five Americans live within 20 miles of our 11,000 Starbucks; 30 percent of American grocery shopping occurs at our 4,500 Wal-Marts. The most familiar element of the American landscape — excepting green highway signs and certain brands of automobiles — might be Subway, which has over 25,000 U.S. locations.

You could be forgiven for thinking, as Simon and Garfunkel sang, “Each town looks the same to me.” From Juneau to Jacksonville, we Americans share, as much as anything, a common commercial experience, a fractal pattern of retail at once comforting and mind-numbing. It stretches the powers of the imagination to think that eating and shopping options in the American city were once as distinct as fingerprints. The shift from mom-and-pops to chains has been one of the defining shifts in American cultural life, and counter-protests have been largely futile, with opponents pegged as sentimentalists standing in the way of progress and low prices.

That is changing. Dozens of American municipalities, mostly small towns with tourism in mind, have passed laws restricting the entry of chain stores. The biggest city to do so is San Francisco: in incremental steps punctuated by a ballot initiative in 2006, the California city famous for liberal activism has enacted the most influential anti-chain legislation in the United States.

You might not realize, walking the streets of Nob Hill, that you are experiencing an urban economy governed by the tightest big-city regulations on “formula retail” in the country. That’s because the San Francisco’s anti-chain net, while unique among large cities, is fairly permeable: three out of four chains that apply for permission to operate in one of the city’s protected zones are approved. Sure, San Francisco is quirky and diverse, true to its reputation, and bursting with independent bookstores, cafes, restaurants and boutiques. But the city isn’t an oasis: as in any other large U.S. city, there are dozens of Starbucks and Subway shops here too.