ABSTRACT
Since the more that a person possesses of a commodity the less is the marginal utility to him, it follows that the larger the quantity that he already enjoys the less sacrifice will he be willing to incur to obtain a further supply. When a person is producing a thing for his own use the sacrifice involved in increasing the supply takes the form of additional labour. After a certain point, even to an industrious person, any kind of work becomes irksome. The point at which work ceases to be pleasant and the further point at which it becomes actively unpleasant will, of course, vary with different persons and different kinds of work, and even with the same person and the same work at different times and places. Some work can hardly ever be actually enjoyable, though use may render the worker indifferent, and with monotonous, disagreeable or hard work the point where it becomes actively unpleasant will be relatively soon reached.
