In New York, even more housing units arent stemming the tide of rising housing costs. Median rents in the city rose 75% between 2000 and 2012, compared with 44% elsewhere in the United States, and yet about 20,000 new units are added per year.

By design, many of the new units arent remotely suited for living situations that would benefit young and single people, older adults, and families. Developers new construction often lacks smaller studios or legally shareable units for unrelated adults, which further crowds out lower-income renters.

People come to New York and start sharing housing so they fit into the city, said Sarah Watson, deputy director of New Yorks Citizens Housing Planning Council. The combined income of two or three unrelated roommates suddenly makes a one- or two-bedroom affordablebut, like the rise in luxury houses, it pushes out people unable or unwilling to combine incomes.

Watson believes increasing affordable housing is tough to do on the market sidebut loosening government regulations would allow smaller developers to build a wider variety of housing. For example, an off-street parking regulation hampers developers in the outer boroughs; theyre forced to create room for vehicles, dramatically increasing the building cost, even though many residents use public transit exclusively.