US Poverty: Divided By a Short Ride, the Bronx and Upper East Side Are a World Apart

It only takes a 10-minute trip up New York's No 6 subway line to see the vast contradictions skewing the performance of the US on the UN's human development index.

In the heart of the Upper East Side, 96th Street station is in the city's 14th congressional district - the highest ranked in the nation, according to the index. Townhouses with neatly tied curtains and ornate railings open on to streets abutting Central Park, only steps away from the city's top museums and art galleries. Billionaire residents include the mayor, Michael Bloomberg, and the financier George Soros.

Average earnings here are $116,000 (£58,000), unemployment is 5.4%, two-thirds of residents are white and six out of 10 people have a university education. Local delicatessens offer gourmet sandwiches and lattes. The streets are lined with independent bookstores and fashion boutiques and there is a preponderance of pet salons pandering to pampered pooches.

Five stops further up the line, 138th Street station is in the Bronx, among the 20 worst-performing districts in the US with a score of 3.4 on the UN's index - which corresponds to the national average around 1985.

A US flag hangs limply in the sun above an liquor store opposite Mitchel Houses, a sprawling estate of local authority flats with a collection of shipping containers in the car park.

"It's no surprise, not to me it isn't," says Gilbert Washington, a maintenance worker, when told the US had fallen down the UN index. He cites healthcare as an obstacle: "A lot of people don't have assistance here even though they work - and the cost of medicine is skyrocketing."

Raymond Petra, a building superintendent, agrees: "They want to send troops to other countries to fight - to Iraq, to Afghanistan, now to Iran - but there's no money here for their own people."

On a street corner nearby, a lackluster stall sells socks, water pistols and DVDs. There's a Caribbean deli, an African restaurant and a dubious-looking bar advertising "live dancing - party time". The local church, St Jerome's, has services in English and Spanish.

In the south Bronx's 16th congressional district, nearly one in seven people are jobless and average earnings are $35,000. Only 8.7% of residents have a university education and the population is ethnically diverse - 65% are Hispanic, 28% black and barely 2% white. To many of New York's wealthier residents, the only reason to venture into the borough is to take in an occasional baseball game at the nearby Yankee stadium.

Only 2.1 miles apart, the two areas have a 56-year gap in development according to the research, which calculates that, at the current rate of progress, it will take until 2041 for the Upper East Side's level of development to be typical nationwide.

Crossing a tree-lined street in the wealthier district, maths teacher Sally Edgar called the findings "embarrassing". She says: "It reflects the government stepping back and expecting big business to provide. There's a tremendous split between the really wealthy and the lower middle class."

Not far from where she is standing, a flat went on sale last year for an eye-watering $50m. The district is known to fans of Sex and the City as the home of the TV series' aspirational, glamorous heroine Carrie Bradshaw.

It was also the stomping ground of Sherman McCoy, the fictional bond trader depicted in author Tom Wolfe's 1987 portrait of Wall Street greed, The Bonfire of the Vanities.