Which parts of stimulus worked best?

Hard to generalize about these things, but a new study says that money for education and law enforcement didn't do much to improve employment. But federal programs focused on low-income households were highly stimulative, along with spending on infrastructure projects. Of course, the researchers must deal with the same old dilemma in sorting out the effects of the stimulus - that is, how to measure what would have happened without the stimulus? The paper was published by the National Bureau of Economic Research, the group that determines when recessions begin and end. (Real Time Economics)