"That cliometrics is an indispensable tool in the study of economic history is no longer a very controversial statement. It is now generally agreed that economic theory, combined with new data as well as historical, statistical and mathematical methods are necessary at the theoretical level, to formulate problems precisely, to draw conclusions from postulates and to gain insight into workings of complicated processes and, at the applied level, to measure variables, to estimates parameters and to organize the elaborate calculations involved in reaching empirical results. This article is an illustration of the author's belief in this principle." (author's abstract