The American Recovery and Reinvestment Act of 2009 (ARRA) is an important policy response to the current deep recession. State and local governments have suffered significant declines in their revenues and, for states in particular, a significant increase in the demand for services, particularly...

This paper reviews academic research on the connections between agglomeration and innovation. We first describe the conceptual distinctions between invention and innovation. We then discuss how these factors are frequently measured in the data and note some resulting empirical regularities....