The fundamental cause of crises thus is seen to be psychological; it is the rhythmic miscalculation of rents and of capital value, occurring to some degree throughout industry, but particularly in certain lines. But this subjective cause in men is given full opportunity for action only when certain favoring objective conditions are present. Most noteworthy of these besides the credit system is a dynamic condition of industry. The past century has opened up new fields for investment on an unexampled scale. Investment has advanced both intensively and extensively in a series of great waves. New machinery and processes have given undreamed of opportunities for enterprise in the older countries, and the physical frontier of investment has moved outward with the march of millions of immigrants to people the fertile wilderness. Such factors disturb the equilibrium of prices both in time and space, give a powerful impulse toward higher values in the older lands, and stimulate the hopes of all investors. When the balance between the capitalizations of various industries and between the rents of the various periods proves to be false, the inevitable readjustment causes suffering and loss to many, but particularly in the inflated industries. But, because of the mutual relations of men in business, few even of those who have kept freest from speculation can quite escape the evils. [Sidenote: Widespread effects on incomes] 4. _Crises must be discussed in connection with other subjects than profits._ In the text-books the subject of the crisis is variously classified. It may well be discussed with money, credit, and banking. It has its bearings on wages, justice in distribution, the theory of interest, and the consumption of wealth. But the reasons for taking it up in connection with the subject of profits are strongest. In no other connection is the presence of the element of speculation and of chance profit and loss in business so forcibly seen. [Sidenote: Their probable mitigation] The income of every class of society is to some extent affected by these more or less periodic fluctuations. They are in part the price paid for progress under the constantly shifting conditions of our dynamic industry. In part they are the proof of industrial maladjustment. The force of the shocks will no doubt be much reduced by better banking and business methods, and by a sound currency system. More important still, the development of moderation, conservatism, and a less speculative spirit among the leaders of business will do much toward softening the asperity of these scourges of industry. PART III THE SOCIAL ASPECTS OF VALUE DIVISION A--RELATION OF PRIVATE INCOME TO SOCIAL WELFARE CHAPTER 38 PRIVATE PROPERTY AND INHERITANCE § I. IMPERSONAL AND PERSONAL SHARES OF INCOME [Sidenote: Functional vs. personal distribution]