Lawrence Hamtil points out that MSCI US index seems expensive versus MSCI World ex USA but sector composition can give a different look.
"At first glance, such a disparity in valuation seems compelling, and it would appear to make sense to underweight U.S. equities relative to the rest of the world, as some have argued. However, I would caution investors to think twice before doing so, as making allocation decisions based solely on aggregated valuations is misguided."
http://www.fortunefinancialadvisors.com/blog/the-correct-way-to-frame-relative-valuations
