Since the outbreak of the current international economic crisis in 2008, the USA and many of the European countries have been tormented by high levels of unemployment and low levels of inflation, interest rates close to zero and fiscal policies of austerity. This book will present new materials and approaches, especially new evidence and new views on the potential problems of public debt, the European Union and the present crisis, Central Banking, hysteresis in an agent based framework, the foundations of macroeconomics and the problems of uncertainty.