Duffhues, P. J. W.2016-12-292016-12-291983Ruch Prawniczy, Ekonomiczny i Socjologiczny 45, 1983, z. 1, s. 151-1670035-9629http://hdl.handle.net/10593/16916In every society it is a firm's task to fulfil the needs of consumers and other producers in the most efficient way. This is to mean that the value created by production should at worst equal the value sacrificed. One of the components of value sacrificed is the cost of debt and equity both of which can be measured on the competitive capital markets as a result of demand and supply. In business finance literature there is much attention to these fields of high theoretical and empirical importance. The cost of debt capital is relatively easy to measure as the discounting rate which equalizes all future payments on the debt instrument (i.e. interest and repayment) to its current market price. The payment of all debt liabilities has to be done before the owners of the company can receive their cost of equity capital, the latter cost being defined as the discouting factor which equalizes all expected future payments to the current market price of the share. Accounting profits of companies are measured gross of thé costs of equity capital, i.e. before costs of equity capital are deducted. Economic profits are defined as accounting profits less costs of equity capital. It may be concluded that from an efficiency point of view research as to the question of the amount of the realized (accounting) rate of return of individual companies is of high importance. Besides research on the measurement of the cost of capital itself should continue. The present article deals with the first research. It concentrates on the measurement and analysis of changes in the accounting rate of return, thereby taking advantage of earlier work done by prof. dr. H. Albach. Eventually, rate of return developments over time may be analyzed using one or two models which are described in the paragraph IV, After some clarifications (par. V) and an illustration of the working of these models by means of a theoretical example (par. VI) empirical attention is given to the analysis of the accounting rate of return developments with regard to the Philips Company. Paragraph VIII summarizes and concludes.polinfo:eu-repo/semantics/openAccessArtykuł