I came across that passage while reading “Industry and Humanity,” by former Canadian Prime Minister Mackenzie King. We'll add this to our previous knowledge on Gresham's Law.
In the reign of Queen Elizabeth, an official named Gresham observed that where different metals were in circulation as coinage and some were better than others of the same nominal value, the coins made of the inferior metal tended to drive the better out of circulation. The better coins were either hoarded or melted down and sold as bullion, were used in the fine arts, or were absorbed in the foreign exchanges. In other words, what Gresham discovered was that cheaper money tends to drive out dearer; that when people begin to discriminate between two coinages, they will invariably pay out the inferior and hoard the better, thus removing the better from circulation. This phenomenon once generally observed came to be described as a “Law,” and was identified with Gresham' s name, since it was Gresham who was first successful in drawing public attention to it. Amongst money-changers, Gresham' s Law of the precious metals is better known than the Ten Commandments.
Something analogous to Gresham's Law will be found to obtain in the case of competing standards in Industry. Assuming there is indifference in the matter of choice between competing commodities or services, but that in the case of such commodities or services the labor standards involved vary, the inferior standard, if brought in this manner into competition with a higher standard, will drive it out, or drag the higher down to its level. This is effected by the opportunity of under-selling which comes, where in such cases human well-being is sacrificed to material ends. The superior standard, not being recognized or demanded, is unable to hold its own, and in time disappears. This Law is just as real and relentless in its operation in Industry as Gresham's Law of the precious metals is with respect to money and the mechanism of exchange. Indeed, a more accurate exposition would describe both as manifestations of one and the same law, which I propose to call the Law of Competing Standards. I see no reason why economists should not recognize the existence of such a law, and incorporate it immediately in economic science as being quite as significant as the Law of Supply and Demand, the Law of Diminishing Returns, or any other Law accorded a place in its nomenclature.
The Law of Competing Standards is doubtless a part of the general Law of Competition, under which the cheaper of two commodities gains in competition a preference over the dearer. What Gresham discovered was an important sequence of the Law of Competition as applied to coinage; namely, the disappearance, in the course of time, of the superior metals. Observance of a like sequence in the case of standards in Industry is highly desirable. As respects labor standards, I believe that recognition of the operation of the Law of Competing Standards over ever-widening areas would do more than aught else to clear up the most baffling problems with which Industry is confronted, and to point the way to a solution of many situations which hitherto have seemed incapable of solution.