Money: The Paper Solution

After four years of bickering, bargaining and brain-racking compromise, 107 nations reached a historic agreement last week in Rio de Janeiro. They found a mutually satisfactory method for overhauling the free world's strained and out-of-date monetary system. Without dissent, finance ministers from the member countries of the powerful International Monetary Fund approved the cautiously controlled creation of what amounts to a new kind of international money—a combination of currency and credit that would supplement the gold, dollars and pounds that now bankroll world trade and investment.

Such an ambitious step has never...