Imagine the following: a collection of debts owed by a highly leveraged borrower with a bad credit record is magically transformed into marketable securities with triple-A yields. How is this miracle performed? It is through the power of financial innovation and free capital markets.

It could be the story of subprime mortgages in the US; but it is not. It is, in fact, the story of government debt in France in the early 18th century. In 1719-20, a financial whirlwind even more dramatic than anything witnessed today swept through France. Shares in the Compagnie des Indes, or the Mississippi Company, rose 1,000 per cent and then fell by 90 per cent in less than two years. The story illuminates current events.