Where the philosophy of unionism is firmly entrenched these two systems of wage payment tend to be so governed by the actions of the wage earners and employers as to lead to approximately the same results. The standard wage under a time-rate system tends to become the wage for an average or customary output. Employers tend to demand at least that output for the standard time wage, and strive to increase the customary output whenever the standard time-wage is increased. And, on the other hand, under a system of payment by results, there is frequently a tendency for the workers to keep their output around a certain general level; which level, indeed, is determined only by all the circumstances governing the group attitude in the particular shop or industry. The "Report on Collective Agreements in the United Kingdom" (1910) has stated this as follows: "Although the main distinction between time wages and piece wages is of the nature described above, it is of importance to note that, whether the method of remuneration adopted be expressed as payment by results or as payment by time, the amount of work performed and the time taken in performing the work are factors, both of which are, to a greater or less extent, taken into account in every agreement for the payment of wages. Thus, on the one hand, the employee who is working on time wages is expected by his employer to turn out in a given time not less than a more or less specifically agreed upon quantity of work--"to do a fair day's work"--while, on the other hand, a list of piece-wage rates usually has an implied, and in some cases has an explicit, reference to the amount of money which can be earned by a man working under the list in a given time."[76] The principle of standardization can and does find expression under either method of wage payment; its adoption does not exclude the system of payment by results. The terms of all such systems, however, should be made the subject of collective agreement. In that way the group interest in a defined minimum standard wage is protected, and the principle of standardization realized. As Prof. Pigou has written, "In order that the piece-wage system, and the benefit to production which it carries with it, may win further ground, what is required is to develop in these more difficult industries an adequate machinery for subordinating piece-wages, ... to the full control of collective bargaining."[77] 5.--Such then, being the leading characteristics of the standard wage, what results can be predicted for an attempt to introduce it throughout industry?