Where formerly a unit of _A'''_ was exchanged for one of _B'''_ or _C'''_, there are now two units of _A'''_ given for two of either _B'''_ or _C'''_, and every one has more things to consume than he formerly had.[3] [3] It will be seen that the maintenance of the present exchange ratios between _A'''_, _B'''_, _C'''_, etc., when costs of all of them are reducing, would require that these costs be reduced in exactly the same degree in each case, and that the quantities sold at the new cost prices should be increased in unequal degrees, so as to bring the different prices to cost levels. The demand for one article is more elastic than is the demand for another. A slight increase in the supply of _A'''_ may cause a large reduction of the selling price, while it may require a great addition to the supply of _B'''_ to produce this effect. There must, therefore, be some changes in the relative quantities of labor in the different subgroups, even though there has been an equal amount of "labor saving" or cost reducing in all of them. This change is so slight in amount as compared with what would be caused by improvements confined to one subgroup, that it is effected with relatively little hardship and mainly by disposing the constant inflow of new labor at the points where it is needed. _Labor attracted toward a Subgroup as a Result of Improvements which are made Elsewhere._--The fact that the demand of consumers for different goods is not uniformly elastic has to be taken into account. There are two distinct kinds of movements in the group system, brought about by improvements in method. Each improvement in and of itself has, as a rule, a labor-expelling effect, but this effect is partly neutralized by general growth in consumption and still more by improvements occurring elsewhere. Labor that is thrown out of the _A_ group would naturally go to group _B_, _C_, etc.; but if, as we have just seen, similar influences tend to expel labor from the _B_ group and the _C_ group, the labor may, for the most part, stay where it is, with the result that more of _A'''_, _B'''_, and _C'''_ is offered to consumers. _The increased output of one group is itself a means of retaining labor in other groups_, even though, thanks to mere methods, that involves making more of every other kind of commodity.