The global movement of people isn’t slowing down. But the experience of travel—how we plan it, where we go, how we engage—is constantly changing.

Woe betide the traveler who forgets her toiletries case, gets peckish, or has a headache at a US airport.

At best, she might find tiny container of Advil or $10 packet of almonds in a Hudson News outlet, sandwiched between a Cinnabon and an Auntie Anne’s Preztels. But why is there no CVS or Walgreens to buy full size bottle of sunscreen post-security? Or god forbid, a place to buy a sunhat or a linen shirt for your upcoming vacation that’s not from Versace or Coach?

Indeed, for people who frequently travel internationally, it will come as no surprise that the majority of American airports are, by comparison to the rest of the world, kind of a dump. It’s something even the current American president and former vice president agree on: Both have described New York’s airports as “third world.”

So why does the self-annointed greatest country in the world seem to greet its visitors with the absolute worst it has to offer? The answer is a mix of geography, economics, and that grand tradition of American life: parking.

Thomas Sineau is an intelligence analyst with CB Insights who focuses on travel and luxury retail. He said that part of America’s problem is you don’t tend to pass through it on your way to somewhere else.

“If you think about London, Amsterdam, Dubai, Singapore or Hong Kong, they are all kind of hubs—not only domestic but international transit hubs,” Sineau said, noting that many of these airports were designed as much for international connections as they were local travelers. “US airports aren’t international transit hubs as much as the others are. And because these other [international] airports are competing against each other [for passenger traffic], they really need to try attract airlines and passengers.”

Somewhat bewilderingly for a country that oozes free market capitalism, Americans have long been averse to turning their airports into profit making machines.

Perhaps the largest determinant of airport quality is its ownership structure. Somewhat bewilderingly for a country that oozes free market capitalism, Americans have long been averse to turning their airports into profit-making machines. Instead, almost all American airports are publicly owned at the local or municipal level—meaning they’re a public good and not allowed to turn a profit.

Elsewhere in the world, airports are more likely to be owned in part or in full by private equity investors, or nationalized at the federal level. The aviation historian Janet Bednarek says these different ownership models dictate what travelers will find there. “In much of Asia and the Middle East, airports are owned by the centralized government and they are created to be these palatial gateways to their countries,” says Bednarek, a University of Dayton professor. “They’re appealing not to local travelers, but to affluent international travelers.”

Airports such as Singapore’s gleaming Changi airport not only have the luxury brands you’d expect, but mid-market chains like Muji, Cotton-on, Uniqlo, and Zara, as well as the convenience chains 7-11 and Watsons.

Thanks to what Bednarek calls this “user-friendly, high retail, highly-accessible” model, there is no reason not to shop.

Meanwhile, in parts of Europe and especially in Britain, airports are semi or fully privatized, turning some of them into what are “basically shopping malls,” as Sineau put it. Not only do British airports have many of the same shops you’d find on the high street or mall, they charge “street pricing” too. This means the fast fashion sundress, Pret a Manger sandwich, and Nivea sunscreen you purchase in the airport cost more or less the same as they would outside. Thanks to what Bednarek calls this “user-friendly, high retail, highly-accessible” model—pioneered by the likes of London Heathrow and Amsterdam Schiphol—travelers find little reason not to shop.

The variable nature of airport retail—time of year, weather, and the economy can all affect passenger traffic—means that many US airports don’t charge retailers a fixed rent charge, but rather, a percentage of their profits, says Bednarek. With no requirement of street pricing—and a stream of captive consumers—prices quickly spiral upwards, which is why travelers must endure the horror of a $9 bag of peanut M&Ms.

Unsurprisingly, this doesn’t encourage travelers to shop: According to Airports Council International, North America falls more than 20% behind every other region when it comes to percentage of non-aeronautical revenue coming from retail concessions.

Another reason why American airports have so woefully underinvested in concessions is because they have historically made a lot of money from parking. This is something an international hub like Dubai—which has much less car traffic because it caters to international travelers—would not be able to rely on. Because there is no profit motive in American airports, Sineau explains, they have historically been less inclined to diversify into other revenue streams outside of of the once-reliable cash cow of parking.

According to FAA numbers reported in the New York Times (paywall) last year, US airports’ income from parking, ground transportation, and rental cars far exceed revenues from food and retail—though that revenue is declining, with the rise of ride-hailing services.

Adding to the US’s shabby airport reputation is the Passenger Facility Charge, which pays for the maintenance and upgrade of actual airport structures. In the US, it has been capped at a measly $4.50 since 2001 and requires an act of Congress to change. Meanwhile, in countries like Canada and the UK, individual airports can charge what they like—and some charge more than ten times what the US does. The result is a more expensive plane ticket, but also, nicer airports.

America may have invented flight—but it certainly didn’t perfect the art of getting there.