North Korean won

Though the North Korean Won, officially called the Korean People's won (KPW) never technically failed it had been steadily devalued since 2002 when the dollar peg was removed.

Estimating Gross National Product is a difficult task because of the dearth of economic data, the national income accounting procedures based on the Marxist definition of production, and the problem of choosing an appropriate rate of exchange for the North Korean Won- the nonconvertible North Korean currency.