The world economy showed remarkably strong and widespread growth throughout most of the second half of the twentieth century. The continuation of that success, however, has been undercut by financial instability and crisis. Weak and uncoordinated macroeconomic policies, inappropriate exchange rate policies, inherently volatile private markets for international capital flows, and weak regulation and oversight of highly risky investments have all played a part. To regain the financial stability that must underpin a renewal of global economic strength will require improvements in both policy making and the structure of the international financial system.