Progressively, and especially since mid-September 2008, it has evolved into a global crisis affecting advanced, emerging and developing economies; and it has spread across economic sectors. The, more or less, synchronised decline or deceleration of economic activity worldwide has been accompanied by a collapse of world trade that has further depressed global economic activity.
A key feature of the current crisis is the mutually reinforcing interaction between, on the one hand, the weakening of economic activity and the rising unemployment and, on the other  BIS Review 53/2009  1  hand, the process of deleveraging and repair of banks’ balance sheets and the persisting tensions in some financial markets.