To Mohamed El-Erian, the world’s major reserve currencies — the dollar, the euro, and the yen — are a bit like your dirty laundry; every shirt is dirty, but compared to the alternatives, they historically have been the “cleanest dirty shirts.”  El -Erian thinks that arrangement will not last forever.  He tells Chrystia that a long-term trade that PIMCO likes is a long position in the currencies of the successful emerging markets — the clean shirts — funded by the currencies of the U.S., the EU, and Japan.