TORONTO (Reuters) - Toronto may be pushing past New York and London as the world's most diverse city, with half its residents born outside of Canada, new census figures show.
But the bigger rivals of Canada's largest city aren't giving up their claims easily, and all sides admit there's no scientific way to measure the elusive diversity goal.
"Certainly there's no doubt Toronto is one of the world's most multicultural cities. It's catching up to New York and London, but it's still the younger one," said Michael Doucet, geography professor at Ryerson University in Toronto.
Toronto has about a third the population of either London or New York, but beats both of them in terms of the percentage of foreign-born residents, according to the government statistics, which were released this month.
About 27 percent of Londoners were born outside Britain, according to 2004 data, while 2006 figures show that about 40 percent of New Yorkers were born outside the United States.
But place of birth is not the only measurement to make a diverse city, and Toronto's rivals point at language and race as factors to consider.
"London is literally the most international city in the world," a spokeswoman for Mayor Ken Livingston said in an e-mail, noting more than 300 languages are spoken there.
New York went even further.
"New York City is the most diverse city on the face of the planet by far," said Guillermo Linares, that city's commissioner of immigrant affairs. "It has representation of about every country that exists."
Official figures show New York with the largest nonwhite proportion of the three cities, at about 56 percent last year. Toronto weighed in with 37 percent, and London with 29 percent, according to data from 2001, which was the last time Britain and Canada polled on race.
"Toronto is in that elite class that I would say includes London and New York of the world's great diverse cities," Andrew Weir, vice president of communications for Tourism Toronto, said modestly.
That's something of a climbdown from the 1990s, when Toronto cited a U.N. study to bill itself as the world's most culturally diverse city.
Doucet said he found no such ranking by the United Nations, and the city soon removed all references to it in its promotional literature.
Because diversity is up for interpretation, there could be other contenders too. Paris, Los Angeles and a handful of other cities could also have a strong claim to be the world's most diverse, officials say.
Toronto, London and New York all have laws on multiculturalism, race relations, or immigrant health and safety as ways to ensure that the cultural mix doesn't become an explosive one.
"Without immigrants, this economy would collapse immediately," Linares said, noting that immigrants account for 45 percent of New York's workforce. "We recognize and embrace what they bring."
Editing by Janet Guttsman