In a recent and insightful paper, Echenique et al. [4] proposed the Money Pump Index(MPI) as an intuitive measure to evaluate the severity of violations of consumer rationality(defined in terms of revealed preference axioms). For practical applications, they suggest usingthe Mean or Median MPI....

Traditionally share price returns and their variance have been explained by factors linked to the operations of the company such as systematic risk, corporate size and P/E ratios or by factors related to the influence of the macro-economic environment. In these models, the institutional...