A new report from the CUNY Graduate Center shows the extent to which the rich are getting richer in New York City, while the poor struggle to gain a foothold.

In 1990, the top one percent of households in New York made $452,000 a year. By the time of the 2010 census, they were making $717,000 a year. During that same period, earnings for the poorest New York families remained nearly flat.

"What we're seeing here is this process of polarization where those at the top can certainly afford to live in this city because of their continually increasing incomes. Those at the bottom often have no choices," said Laird Bergad, director of the Center for Latin American, Caribbean and Latino Studies at CUNY, and author of the report.

There's some evidence that New York's high housing prices force some middle-income earners out of the five boroughs, which further widens the gap between the rich and the poor, Bergad added.