We develop tests for mean-variance efficiency of international equity
markets for ten OP countries. A Wald test that allows for time-varying
variances of excess returns rejects a version of MVE. The source of t
he rejection is not entirely clear, so we use a minimum distance estim
ator to estimate the mean-variance efficiency model. While we formally
reject the MVE constraints in this model, the estimated constrained a
sset demand equations are revealing.