=12. Productive Labor.= The wages paid to the workmen for labor spent on productive work which is offered by the manufacturer for sale, and from which the business derives its regular revenue, is properly classed as _productive labor_. In other words, the amount of productive labor is commensurate with the productive output. It is frequently asked whether labor spent on plant extensions or new equipment, when made for one's own use, may be considered productive labor and should carry its share of the expense in its distribution. Most assuredly, yes. If this same work were performed to be sold again in trade it would be considered productive labor and the expense would be added. The reverse is also true; if it were purchased from another manufacturer he would treat it as productive labor, and include expense in his cost and selling price, and the purchaser would have to pay for it, and would carry same in his ledger, in his plant or equipment accounts, and on his balance sheet as an asset. The only difference, if any, is in making new equipment himself, in which case it goes on his books at the cost price to him, thereby saving the manufacturer's profit he would have to pay if he purchased it. Is it, then, any less productive labor because a manufacturer prefers to make his plant extensions or new machinery, himself, instead of buying? It does not appear so; it certainly is productive labor. =13. Non─Productive Labor.= All other labor, not distinctly productive as just outlined, must be classed as non─productive. This includes _clerks_ and _offices_, _foremen_, _assistants_, _watchmen_, _repairs_ and _renewals_, _small tools_, etc., and all the many expense men not working on product but necessary to keep the plant in repair and operation. Non─productive labor is a question of keeping the factory organization and management up to concert pitch, and is not regulated by the quantity of production. Inter─department work in a plant often raises an interesting question. Shall labor expended by one department on repairs for another department receive credit for same as productive labor? The foreman of the department often claims that the repairs his men are doing for another department are just as much production, so far as he is concerned, as though his men were building a machine for sale, and should shoulder part of his expense. In a certain sense, all labor is productive, and from a selfish point of view, the foreman's argument is a fair one. But from the broader view of the manufacturer, all such inter─department repairs, or similar work, are a part of the operating expense of the plant, and are necessary for the up─keep of the equipment; they are not made for sale, as is a production order, and must be carried as expense──non─productive labor.