Earlier this month, at the Park Hyatt Hotel in Zurich, Switzerland, the consulting firm Henley & Partners held a press conference to unveil its latest contribution to the international citizenship marketplace. The company, whose main business is helping wealthy individuals find new homes for themselves and their money, publishes a popular annual ranking of the relative worth of every passport in the world. But, at the press conference, the company’s leaders announced that they had created a new measurement ranking, better suited to the modern world: the Henley & Partners-Kochenov Quality of Nationality Index, or Q.N.I.

The press conference was overseen by Chris Kalin, the Swiss chairman of Henley & Partners, and Dimitry Kochenov, a scholar of European citizenship law at the University of Groningen, in the Netherlands, whose research contributed to the creation of the Q.N.I. In a hundred-and-ninety-one-page report about the Q.N.I., which was also released this month, Kalin and Kochenov wrote that traditional metrics take states “somewhat too seriously.” The Q.N.I., on the other hand, was designed to capture the “objective value of world nationalities.” This value is relevant for those people with bank accounts large enough to acquire new passports and countries of residence—the target demographic of Henley & Partners.

“You shouldn’t rejoice with just one great passport,” Kochenov advised the audience at the press conference.

According to Kalin and Kochenov’s report, the Q.N.I. ranks “nationalities—the legal statuses of attachment to states—rather than states per se, taking into account the increase in world migration flows as well as the lack of a correlation between the nationality held by a growing number of active individuals and the countries where their businesses are established and their lives are lived.” In other words, the new ranking acknowledges that, today, holding any given nationality need not mean residing in, or even identifying with, the corresponding nation. The Q.N.I. rewards nationalities that offer more visa-free access to other countries, and greater “settlement freedom,” like member states of the European Union. A Spanish citizen, for example, can relocate to Germany easily. An Afghan citizen cannot.

Kochenov, wearing horn-rimmed glasses and a green polka-dot bow tie, spoke to the business-casual crowd about the changing fortunes of nationalities around the world. “If you are Bulgarian, you can almost feel it with your skin as you travel easier and easier around the world,” he said. According to the Q.N.I., Bulgaria, Romania, and Croatia have seen the value of their nationalities rise dramatically since joining the European Union, while the value of Ukrainian and Syrian nationalities is in free fall. “Brexit is my favorite!” Kochenov said, arms waving at a chart showing just how much the value of British nationality will decline if the U.K. votes to leave the E.U. later this month. “After Brexit, we're speaking about the ‘Argentinianization’ of British citizenship.” The Q.N.I. ranks Argentine nationality thirty-seventh in the world, the final slot in the group deemed “very high quality.” The U.K., for now, sits in eleventh place.

Kochenov pointed out another of his favorites: Georgia, in one-hundred-and-third place, the only “counter-trend country” on the list. “It’s a country that welcomes the whole world to settle and to work without any hassle,” he said. “You simply fly there, sometimes they give you a bottle of Kindzmarauli at passport control—you need to fly in on Sunday—this happened to me once! And they say, ‘Welcome to Georgia!’ ”

Kalin and Kochenov met by chance a few years ago, in an airport lounge in Zurich. They began to discuss Henley & Partners’ original ranking system, and Kochenov eventually argued that the company’s system was flawed. “The limitations of his index were so ridiculous and so overwhelming, so I decided to do something that would actually make sense,” Kochenov told me last week. Kalin, for his part, saw the benefit of “an enhanced view”—a ranking that reflected why visa-free access to the European Union is more valuable than access to North Korea or Burundi.

Henley & Partners advises clients interested in “citizenship planning,” and helps clients choose among the small group of countries where citizenship can be obtained through various investments—ranging from hundreds of thousands to millions of dollars. The firm also advises governments on how to make their nationalities more enticing to wealthy foreigners, mostly by helping them create citizenship-for-investment programs and visa-waiver treaties.

In the nineteenth century, the British lawyer and legal theorist A. V. Dicey proposed the creation of a common citizenship, or “isopolity,” between the United States and the United Kingdom. Dicey argued that such a system would require “no necessary connection whatever with national or political unity.” Kochenov considers Dicey an inspiration for his current work. “We go through schooling, we go through this profound process of indoctrination to think of our country as a special place, the reasons for which are not revealed to us,” he told me. “This is how all the totalitarian regimes work, but also many democracies.”

The U.S. ranks twenty-eighth^ ^on the Q.N.I., behind nearly every E.U. country. Kalin told me that the U.S.’s rank is partly due to its restrictive immigration policy, and partly because “there are so many weapons, and a high incarceration rate.” But Kochenov sees the U.S. as a state where “nationalism is still in place,” where “the mythical correlation between the people and the soil is more important than the creation of opportunity for interesting people to get in.”