In addition to Hong Kong, the MTR Corporation runs individual subway lines in Beijing, Hangzhou, and Shenzhen in China, two lines in the London Underground, and the entire Melbourne and Stockholm systems. And in Hong Kong, the trains provide services unseen in many other systems around the world: stations have public computers, wheelchair and stroller accessibility (and the space within the train to store them), glass doors blocking the tracks, interoperable touch-and-go fare payment (which also works as a debit card in local retail), clear and sensible signage, and, on longer-distance subways, first-class cars for people who are willing to pay extra for a little leg space.

How can Hong Kong afford all of this? The answer is deceptively simple: “Value Capture.”

Like no other system in the world, the MTR understands the monetary value of urban density—in other words, what economists call "agglomeration.” Hong Kong is one of the world’s densest cities, and businesses depend on the metro to ferry customers from one side of the territory to another. As a result, the MTR strikes a bargain with shop owners: In exchange for transporting customers, the transit agency receives a cut of the mall’s profit, signs a co-ownership agreement, or accepts a percentage of property development fees. In many cases, the MTR owns the entire mall itself. The Hong Kong metro essentially functions as part of a vertically integrated business that, through a "rail plus property" model, controls both the means of transit and the places passengers visit upon departure. Two of the tallest skyscrapers in Hong Kong are MTR properties, as are many of the offices, malls, and residences next to every transit station (some of which even have direct underground connections to the train). Not to mention, all of the retail within subway stations, which themselves double as large shopping complexes, is leased from MTR.

The profits from these real estate ventures, as well as that 85 percent farebox surplus, subsidize transit development: proceeds pay for capital expansion as well as upgrades. The MTR’s financial largesse means that the transit system requires less maintenance and service interruptions, which in turn reduces operating costs, streamlines capital investments, and encourages more people to use transit to get around. And more customers means more money, even if fares are relatively cheap: most commutes fall between HK $4 and HK$20 (about 50 cents to $3), depending on distance. (In London, by comparison, a Tube journey can cost as much as $18). Fare increases in Hong Kong are limited by regulations linking fares to inflation and profits, and the territory’s government recently started giving a HK $600-per-month travel stipend to low-income households, defined as those earning less than HK $10,000 a month.