 Government and central-bank policies are needed because the "long run" may be very long.Keynes' stress on the importance of centralized coordination of macroeconomic policies (e.g., monetary and fiscal stimulus) and of international economic institutions such as the World Bank and International Monetary Fund (IMF), and of the maintenance of a controlled trading system was emphasized during the 2008 global financial and economic crisis.This has been reflected in the work of IMF economists and of Donald Markwell.