Japan experienced a boom-and-bust cycle in the real estate and stock markets almost 20 years earlier than Europe. Since the bursting of the Japanese bubble economy, the country has fallen into a deep recession and has experimented with crisis therapies in the form of unconventional monetary expansion, Keynesian fiscal stimulus, and recapitalization of financial institutions. Japan reached a low interest rate environment in the mid 1990s and has accumulated an exceptionally high level of public debt during more than two decades of economic stagnation. This paper compares the boom-and-bust cycles in Japan and Europe with respect to the reasons for excessive booms, the characteristics of the crises, and the (potential) effects of the crisis therapies. It is argued that in both Japan and Europe the consequences of expansionary monetary and fiscal policies include the hysteresis of a low-interest rate and high government debt environment, the erosion of the allocation and signaling functions of the interest rate, the gradual quasi-nationalization of financial institutions, as well as gradual real income losses. The economic policy implication for Europe and Japan is the timely exit from crisis therapies in the form of excessively expansionary monetary and fiscal policies.