A non-profit group has found that the city's financial bonus program for teachers hasn't improved student achievement.
The RAND Corporation, which released a report on Monday, said it studied 200 "high needs" schools between 2007 and 2010.
Mayor Michael Bloomberg said Monday that the incentive program didn't work the way he had hoped.
"We've got to constantly look at new things," Bloomberg said. "Consult with everybody, listen to every new idea. And if they don't work, you stop them, because if you don't stop them, you don't have the money to try new things."
Barbara Morgan, a spokeswoman for the city's Department of Education, said the financial incentive program was suspended in January "out of concern about its effectiveness. This study confirms that was the right decision."
Morgan also said the city spend $56.3 million on the program, including $21 million in private funding during its first year.