During the recent decades the financial sectors of developed and developing countries have changed remarkably. There has been a major increase in the degree of financial intermediation, and new financial instruments, triggered by national and international legal liberalisation and by the development of communication technologies, have been developed. The overall importance of financial factors for real investment and growth of non-financial business has risen. Finally, the power of shareholders in joint stock companies seems to have increased vis-à-vis management and labourers. These and other changes as well as their effects on the macro-economy require deeper investigation, in particular since the US sub-prime mortgage crisis has been spreading over international financial markets and has already affected real development in the negative.