Hypotheses about the relation of various factors to the standard of living or to the standard obtaining in the social class under investigation may be classified into three groups: (1) utility hypotheses, including (a) relations between laws of supply and price and of the budget, (b) the law of diminishing returns or of rent, and (c) the marginal utility analysis; (2) the Engelian hypotheses which attempt to correlate the distribution of the budget with ideas of well-being; and (3) the Le Play hypotheses which attempt to correlate the family budget of expenditures with the social consequences of consumption, particularly in the field of social organization. Many of the ideas conflict; very few have been tested for complete validity under all conditions. Most of the laws have an economic bias, neglecting many of the fundamentals of the standard of living from the sociological viewpoint. The analyses have been largely biased by the assumption of an immediate reaction between an individual and his present co...