Doyle is correct. When countries have low per capita income levels (as in BRIC countries), their currencies tend to be weak and below levels predicted by PPP. If the current value of the Brazilian real is $0.53 and the value predicted by PPP is $0.60, then the currency is undervalued by PPP standards.
Rodriguez is correct. As the BRIC countries mature and income rises, their currencies will appreciate and converge toward the value predicted by PPP
