June 16, 1916] 



SCIENCE 



843 



DEATH RATES AND EXPECTATION 

 OF LIFE 



Director Sam. L. Rogers, of the Bureau of 

 tte Census, Department of Commerce, is soon 

 to issue a unique set of tables, the first of their 

 kind which have ever been prepared by the 

 United States government. These tables, 

 which were compiled in the division of vital 

 statistics, under the supervision of Professor 

 James W. Glover, of the University of Michi- 

 gan, show death rates and expectation of 

 life at all ages for the population of the 

 six New England states, ISTew York, New Jer- 

 sey, Indiana, Michigan and the District of 

 Columbia (the original death-registration 

 states) on the basis of the population in 1910 

 and the mortality for the three years 1909, 

 1910 and 1911. They are similar to the " life 

 tables" prepared by life insurance companies, 

 but differ from them in that they relate to the 

 entire population of the area covered, whereas 

 the life insurance tables relate only to risks se- 

 lected through medical examination and other- 

 wise. 



Expectation of life, at birth, in a stationary 

 population — that is, one in which the births 

 and deaths were equal and were the same from 

 year to year, and in which there was no immi- 

 gration or emigration^ — would be the same as 

 average age at death, which is calculated by 

 totalizing the ages of all deceased persons and 

 dividing the result by the number of deceased 

 persons. 



According to these tables the average expec- 

 tation of life, at birth, for males is 49.9 years ; 

 for females, 53.2 years; for white males, 50.2 

 years; for white females, 53.6 years; for na- 

 tive white males, 50.6 years; for native white 

 females, 54.2 years; for ISTegro males, 34.1 

 years, and for Negro females, 37.7 years. Fe- 

 males are thus longer lived than males to the 

 extent of more than 3 years, and in the ease of 

 the native whites and Negroes, more than 3^ 

 years. 



The expectation of life at the age of 1 is 

 considerably greater than at birth, being 56.8 

 years for native white males and 59.5 for na- 

 tive white females, and reaches its maximum 

 at the age of 2, when it is 57.5 for the former 



class and 60.1 for the latter. At the age of 12 

 the average native white male's expectation of 

 life is 50.2 years; at 25 it is 39.4 years; at 40, 

 28.3 years; at 50, 21.2 years; at 60, 14.6 years; 

 at 70, 9.1 years, and at 80, 5.2 years. Simi- 

 larly, at the age of 12 the average native white 

 female's expectation of life is 52.6 years; at 

 25 it is 41.8 years; at 40, 30.3 years; at 50, 

 22.8 years; at 60, 15.8 years; at 70, 9.8 years, 

 and at 80, 5.5 years. 



A part of the difference between expectation 

 of life for men and for women is due to the 

 greater number of violent deaths among men. 

 Nearly four fifths of these violent deaths — 

 suicides, homicides and accidental deaths — are 

 of males, and such deaths form about 7 or 8 

 per cent, of the total nimiber occurring each 

 year. This fact, however, does not aceoujit 

 fully, or even in major part, for the greater 

 longevity of women. An examination of the 

 tables discloses a lower death rate for females 

 than for males during each of the first 12 

 months of life and, in the case of the native 

 whites, during each year of life up to the age 

 of 94. During the first month of life the death 

 rate among native whites is nearly 28 per 

 cent, higher for boys than for girls, and during 

 the first year it is more than 20 per cent, 

 higher. 



The enormous waste of infant life which 

 still goes on, although medical science has 

 done and is doing much to arrest it, is shown 

 by the exceedingly high death rates which pre- 

 vail among infants under 1 year of age. Of 

 100,000 native white boy babies bom alive 

 4,975, or almost 5 per cent., die during the first 

 month, and 12,602, or 12.6 per cent., die within 

 one year. The girl baby's chance of life is con- 

 siderably better, the death rate among native 

 white females during the first month being 

 3,894 per 100,000 born alive, or less than 4 

 per cent., and during the first year 10,460 per 

 100,000, or nearly 10.5 per cent. 



On its first birthday, however, the likelihood 

 that a child will die within the year is only 

 about one fourth as great as it was at birth, 

 the death rate among native whites during the 

 second year being 2,841 per 100,000 for 

 males and 2,610 per 100,000 for females. The 



