Abstract :
IT IS ADMITTEDLY difficult to anticipate future variations in some of the factors involved in economic studies, such as taxes and probable life, just as it is difficult for the transmission-line designer to anticipate future loads and power factors. But in neither problem is the correct arithmetic a matter of personal judgement; the arithmetic of economic comparisons is as rigorous and clear-cut as Ohm´s Law. This article deals with the appropriate treatment of return on the investment, depreciation, taxes, and insurance.
