A new report says that a New York City program is not creating enough affordable housing units.

The optional program encourages developers to include low- and middle-income apartments in exchange for being allowed to construct bigger buildings.

According to the New York Times, the report by City Councilman Brad Lander’s office says the incentive isn’t producing enough of the units.

The report found that the “inclusionary zoning” program has created only some 2,700 permanently affordable units since 2005. That’s less than 2 percent of all city apartments produced during that period.

The city Department of Housing Preservation and Development says the downturn in the economy in recent years has affected the program. But it says the program is picking up now.

(AP)