This is odd, isn't it? Since the 1970's and 1980's, New Yorkers have steadily gotten healthier. Most boroughs now exceed the national average. The fifth borough, the Bronx, is one of the poorest areas in the United States, and even the Bronx is catching up.
Some give credit to Mayor Michael Bloomberg's health initiatives. Bloomberg has taken some strong measures, but the big jump appears to have been in the 1990's, well before Bloomberg became Mayor.
Several in the comments section at Washington Monthly credit walking. New Yorkers do a lot of walking. One credited walking subway stairs alone for his being able to lose 20 pounds!
There might be something to that. The Dutch, for example, seem to be a very healthy people. As I like to say, their young people look like athletes, and their old people look like diplomats. It's because they ride bicycles and walk. Everyone does, and it shows. They look healthy.
The biggest jump in New York appears to have been in the 1990's. I'd give credit to a booming economy of that period, the longest sustained period of prosperity in American history. I traveled a lot during that time. Everywhere, in nearly every major city, there were new construction projects downtown. You could see the prosperity.
New York, the nation's leading city, reflected that prosperity par excellance, and I wouldn't be surprised if that were a factor in its rise in life expectancy. Notice, too, that all boroughs rose rather sharply together. A rising tide lifts all boats!
You'd think our nation's corporate leaders would understand something that any 6th grader knows, which is that if everybody is better off, everybody is better off. A healthier, stronger people produces more and buys more. Corporations gain along with everybody else. It's a win-win.
Besides, people at work walk more. That alone may explain why they are healthier, but a positive attitude definitely helps. It's hard to have one when the atmosphere is bleak and the opportunities are few.