96 BELL SYSTEM TECEINICAL JOURNAL 



respect. Concavity upwards represents a distribution which is less 

 skew than the theoretical logarithmic skew curve, and concavity 

 downwards a distribution of greater skewness. No great importance 

 can be assigned to small differences of this sort, as they are not perma- 

 nent betw^een successive surveys, whereas the general type of the 

 distribution is quite constant for a given city. 



The justification for assuming that rents follow the logarithmic 

 skew curve is made stronger by certain data from Volume 19 of the 

 report of U. S. Immigration Commission made in 1912. This com- 

 mission collected a large mass of data concerning the living conditions 

 of families of the immigrant type. The data are classified by nation- 

 ality of head of family, by income, etc. Distributions of amounts 

 paid for house rent per apartment, per room and per person for certain 

 nationalities are shown in Fig. 5. The data shown were chosen from 

 those classes which were made up of the largest numbers, and the 

 deviations from straight lines shown by data for other groups are in 

 both directions, so the straight line relation may be considered fairly 

 representative. It may be noted that the rents per month per person 

 show a greater dispersion than the rents per room or per apartment. 

 These latter moreover show as small a spread as do rents for any of 

 the cities studied as a whole. 



Fig. 5 also shows the distribution of British house rents at intervals 

 during the period 1890-1913. There has been a gradual but steady 

 decrease in the dispersion of rents during the period covered. Unless 

 the relation between rents and incomes has radically changed, this 

 means that the inequality of distribution of wealth has been decreased, 

 and that the condition of the poor has been improved as compared 

 to that of the rich. Data for 1830 indicate that the inequality of 

 distribution was distinctly greater at that date than in 1890. Changes 

 in the relative condition of the rich and poor may be readily demon- 

 strated by charts of this kind, but of course conclusions regarding 

 absolute degrees of well-being must be reached by other means. 



Distribution of Rents Compared with that of Incomes. Significant 

 conclusions regarding the relation between rents and incomes may be 

 drawn from a comparison of their respective distributions. Fig. 6 

 shows a detail curve for income distribution in the United States 

 based on preliminary data of the National Bureau of Economic 

 Research. These data are subject to revision but are the best avail- 

 able and are sufficiently accurate for comparative purposes. The 

 usual way to chart income distribution assumes conformity with 

 Pareto's law which says that the frequency curve of incomes may 

 be plotted as a straight line on double logarithmic paper, either on a 



