Ferenc Janossy (1914-1997) was one of the most original Hungarian economists of the state-socialist period. His research focused on historic macro-processes of the development of the real economy. According to his trend line theory the upper limit of growth of national economies is prescribed by the labour supply - in terms of its profession structure and ability to adapt. This idea is of extreme importance in the process and in the close of the restructuring periods that follow recessions. He recognized these in the faltering of reconstruction boom after the Second World War and based his theory on it. The examination of the present occurrences shows this dependence to be valid also in the flows fallowing the system change in Central and Eastern Europe.