The effects of the financial crisis are still being felt, five years on. This article, the first of a series of five on the lessons of the upheaval, looks at its cause: “The collapse of Lehman Brothers, a sprawling global bank, in September 2008 almost brought down the world’s financial system. It took huge taxpayer-financed bail-outs to shore up the industry. Even so, the ensuing credit crunch turned what was already a nasty downturn into the worst recession in 80 years. Massive monetary and fiscal stimulus prevented a buddy-can-you-spare-a-dime depression, but the recovery remains feeble compared with previous post-war upturns. GDP is still below its pre-crisis peak in many rich countries, especially in Europe, where the financial crisis has evolved into the euro crisis. The effects of the crash are still rippling through the world economy: witness the wobbles in financial markets as America’s Federal Reserve prepares to scale back its effort to pep up growth by buying bonds.”

• See also Global Institutions after the Crisis, by Ngaire Woods, Dean of the Blavatnik School of Government, University of Oxford