According to a New York Times article documenting Murray Hill (a post-grad den for bros) in New York City. Within the limits of the fratty neighborhood lies a high-rise apartment building with 700+ apartments (each probably containing 3 people thanks to fake walls).
In that building alone, 70.5 percent of households are occupied by singles, and 79.5 percent of adults are college graduates. That means in one square block of Manhattan, there are approximately 1000 single people, most of whom are under the age of 30.
We have our own theories on why there are so many singles in New York, but you can figure those out for yourself, just read the commentary in the NYT article…