I'm beginning to think that there may have been a hidden purpose behind the seemingly random sequence of events that led me from leafy London to the potholed poverty of Louisiana's biggest city.

Researchers from the University of Warwick in England and Hamilton College in New York have published a study of happiness in the USA. Its conclusions will leave most New Orleanians a little bit proud, but not in the least surprised.

They took the results of a major survey of self-reported happiness ratings in every US state, and compared these with objective quality-of-life measures such as climate, population density and house prices. And the state that ranked top based on all of these benchmarks was not Florida, not California, not Hawaii, but Louisiana.

I can tell you exactly why this is. No, on second thoughts I'll leave it to Dan Baum, the New Yorker columnist whose classic work of nonfiction, Nine Lives, encapsulates New Orleans better than any other. Of course Lousiana isn't just about New Orleans, but the city is home to a quarter of the state's population, and I like to think that a little of its lackadaisical outlook has rubbed off on its neighbours.

Most visitors to New Orleans start asking impolite questions: Why has the rebuilding since Katrina gone so slowly? Why do you put up with such corrupt and incompetent politicians? How can you waste so much money on Mardi Gras when you're still living in trailers? Doesn't anyone in this city ever show up on time?

New Orleanians are hard to offend. Stop thinking of New Orleans as the worst-organized city in the United States, they say. Start thinking of it as the best-organized city in the Caribbean.

While the rest of Americans dream and scheme and chase the horizon, New Orleanians are masters at the lost art of living in the moment. If we're doing okay this minute, goes the logic - enjoying one another's company, keeping cool, and maybe having something good to eat - of what earthly importance is tomorrow or next week? Given the fragility of life, why even count on getting there? New Orleannians are notoriously late showing up, if they show up at all, because by and large they don't keep calendars. Calendars are tools for managing the future, and in New Orleans the future doesn't exist.

Actually, we're not all living in trailers any more. When I first flew in to Louis Armstrong International Airport, three years ago and a year after Katrina, the city was awash with white FEMA trailers, but now they've nearly all gone. Life is getting better, but you just have to be patient. Fortunately, patience is a virtue that's in abundant supply round here.