Governor of Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Janet Napolitano Superintendent of Public Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tom Horne Student Regent (voting), appointed to June 2004 ....

We give a simple explicit formula for turnover reduction when a large number of alphas are traded on the same execution platform and trades are crossed internally. We model turnover reduction via alpha correlations. Then, for a large number of alphas, turnover reduction is related to the largest eigenvalue and the corresponding eigenvector of the alpha correlation matrix.

More police reduces crime but little is know about the mechanism. Does more police deter crime by reducing its attractiveness, or is the reduction driven by an incapacitation of recurrent criminals? This paper exploits micro-level data on single robberies together with redeployments of two police forces within a city, providing first evidence of (negative) incapacitation that is driven by reduc...