Figure 2 traces the trajectory of sum of gross public and private external debt/ GDP since 1970 for the same of sample of 22 advanced and 48 emerging market economies. The overlap and interaction between different types of debt is particularly acute when it comes to external debt. As Reinhart and Rogoff (2009,2011) note, the historical record indicates that private external debt are often absorbed by the sovereign during a debt crisis.
Led by European, the surge in external debt of the advanced economies since the early 2000s is unprecedented; for example, it dwarfs the late 1970s to early 1980s lending boom to emerging market.3 For Europe as whole, public and private external debt are already more than double the 90 percent threshold and constitute a considerable source of uncertainty.