competition keeps on until the receipts are only enough to pay the operating expenses, still the road is not abandoned because then the capital invested, in it would be a complete loss. Changes in productive processes often lessen the demand for a line of goods; but the owners of the capital invested in factories and machines for making these goods may often cause them to be continued in operation at a loss rather than lose all that they have invested, and because they hope for better days and a renewal of the demand. For the sixth law of competition we have: _In any given industry the tendency toward the death of competition (monopoly) varies directly with the amount of capital required for each competing unit._ This law is proven in part by the preceding laws; for when a large capital is required for each competing unit, the number of competitors will be small and the tendency toward monopoly will be strong; but it may also be proven independently. Business men, before they form a combination, are certain to ask whether new competitors are likely to enter the field against the combination. Now, as we have seen in very many cases in the preceding chapters, when there is a great amount of capital required, new competitors will be very unlikely to enter the field. If there is but little capital required, they will be very apt to do so, being tempted by the prospect of large profits at the monopoly's prices. But they know that the combination will concentrate its strength to fight them in every way; and if they must invest a great deal of money in buildings, plant, etc., to start operations, they will be apt to think twice before they take the field against the combination. The seventh law of competition is: _In any given industry in which natural agents are necessary, the tendency toward the inequality of competition (monopoly) tends to vary directly with the scarcity of available like natural agents._ The influence of limited natural agents in promoting the growth of monopolies is a matter of the greatest importance. That the law is true, is evident upon slight investigation. For if some especial gift of Nature is a necessity to any industry, and those who are engaged in that industry can secure all the available gifts of Nature of that sort, there is no opportunity for new competitors to enter the field.