Before revision:  A theoretical analysis illustrates how an optimal dynamical policy reduces both recession duration and severity, and increases the value of GDP at all times. We propose a criterion to distinguish a posteriori a dynamical policy from a static one. Finally, we predict that Ukraine will recover its current and constant dollar 1990 GDPs in 2009 and Moldova in 2015 in current dollars and 2009 in constant dollars .
After revision:  We then argue that it can be used to detect shocks and discuss its predictive power. Finally, a two-sector theoretical model of recession and recovery illustrates how the severity and length of recession depends on the dynamics of transfer rate between the growing and failing parts of the economy .