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...

Issue: When benchmarking (as in engagement, work‐ stress, safety, or performance‐related applications), the use of normative scores can be a big mistake. Because if the norm group characteristics change in any way, the entire benchmarking process is rendered problematic. More importantly, if score magnitudes are considered related to performance, then it is the actual score which carries that r...

this survey is carried out with the major objective of studying various water treatment plants in iran. the emphasis was on the plants being fed by surface water resources; also the clarification unit was taken as the major one among treatment processes. in this way 25 water treatment plants located in different cities of iran were studied from the point of view of technical specifications chem...

Based on the R&D activities of Shanghai’s high-tech industries during 2010 to 2012, this paper uses super efficiency DEA model to analyze and evaluate the R&D efficiency of Shanghai’s hightech industries. The results show that the R&D efficiency of Shanghai’s high-tech industries has dissimilitude. The R&D efficiency values of some high-tech industries are relatively low. There are many redunda...