really tending to cause this difference of demand, are continually occurring, sometimes to such an extent, that the rate of interest on the best mercantile bills has been known to vary in little more than a year (even without the occurrence of the great derangement called a commercial crisis) from four, or less, to eight or nine per cent. But, at the same time and place, the rate of interest is the same, to all who can give equally good security. The market rate of interest is at all times a known and definite thing.
It is far otherwise with gross profit; which, though (as will presently be seen) it does not vary much from employment to employment, varies very greatly from individual to individual, and can scarcely be in any two cases the same. It depends on the knowledge, talents, economy, and energy of the capitalist himself, or of the agents whom he employs; on the accidents of personal connexion; and even on chance. Hardly any two dealers in the same trade, even if their commodities are equally good and equally cheap, carry on their business at the same expense, or turn over their capital in the same time. That equal capitals give equal profits, as a general maxim of trade, would be as false as that equal age or size gives equal bodily strength, or that equal reading or experience gives equal knowledge. The effect depends as much upon twenty other things, as upon the single cause specified.
But though profits thus vary, the parity on the whole, of different modes of employing capital (in the absence of any natural or artificial monopoly) is, in a certain, and a very important sense, maintained. On an average (whatever may be the occasional fluctuations) the various employments of capital are on such a footing as to hold out, not equal profits, but equal expectations of profit, to persons of average abilities and advantages. By equal, I mean after making compensation for any inferiority in the agreeableness or safety of an employment. If the case were not so; if there were, evidently, and to common experience, more favourable chances
