Introduction: A complexity approach to economic challenges

The OECD launched its New Approaches to Economic Challenges (NAEC) initiative in 2012 to reflect on the lessons for economic analysis and policy making from the financial crisis and Great Recession. European Central Bank Governor Jean-Claude Trichet said that: “As a policy-maker during the crisis, I found the available models of limited help. In fact, I would go further: in the face of the crisis, we felt abandoned by conventional tools”. But even before the crisis Greg Mankiw from Harvard University lamented that “macroeconomic research of the past three decades has had only minor impact on the practical analysis of monetary or fiscal policy”.