414 lotka: objective standard of value 



or, since the price P of a commodity is proportional to its ''value 

 in exchange/'^ 



PiPi - P2P2 = ... (10) 



Equations (6) and (9) or (10) are those derived by Jevons by a 

 somewhat different process. This set of equations determines a 

 certain definite distribution of labor when the values of co, co' and 

 p and p' are given for each commodity and form of fatjgue — and 

 this is as far as Jevons carries the discussion of the problem. 



For our present purposes the equations thus arrived at serve 

 merely as a starting point on which to base our investigation. 

 Jevons assumes certain characteristics co, co', p, p', of the repre- 

 sentative individual as given, and determines the distribution of 

 labor which follows from such a set of characteristics. We, 

 discussing the case from the point of view of evolution, are inter- 

 ested in the effect produced by variations in these characteristics. 



Let us examine, from this standpoint, the basic equations (3) 

 and (4). These equations clearly bring out the fact that the dis- 

 tribution of labor in several pursuits depends, for a given type of 

 individual, on two kinds of factors: 



1. On the productivity of labor in different pursuits, or, as we 

 may express it in closer harmony with our present point of view, 

 on the productive "efficiency" of the representative individual in 

 different kinds of labor. Thus, in particular, it is obvious that 

 if, other things remaining equal, all the efficiencies p are increased, 

 the total amount of commodities produced and thus rendered 

 available for consumption will be increased. Normally this will 

 bring with it a rise in the rate of increase of the community or 

 race, i.e. a better adaptation of the race to its environment, or 

 greater "fitness." 



2. On the other hand, given a certain set of values of the pro- 

 ductivities or efficiencies p, the distribution of labor will depend 

 on the values which the individual sets upon the several commodi- 



' Loc. cit. pp. 184, 186, 187. In place of the prices P1P2 • ■ Jevons introduces 

 into equation (10) the quantities Qii Qi of the several commodities interchange- 

 able on the market. These quantities Q are of course inversely proj^ortional to 

 the prices P. 



