Excess female mortality and the balance of the sexes in the population: an estimate of the number of "missing females".

The effect of sex differences in mortality and determining the ratio of males to females in the population is considered. There is discussion of the sex ratio what is normative what affects the ratio and different means of substantiating sex differentials. The example is given of the Regional Model Life Tables which indicate a general prevalence of lower death rates for females and the female advantage in life expectancy. The means ratio of male to female life expectancy is .924 at 80 years. In a stationary population when the masculinity ratio at birth is 1.06 the ratio of males to females using West model life tables ranges between .979-1.003. Given a higher male mortality at every age the ratio of males to females is greatest at birth and declines with age i.e. a population with younger age groups will have a higher proportion of males than an older population. The stable population incorporating West life tables has a male ratio of .997 with moderate mortality and with a 2% natural increase has a male ratio of 1.022. The sex ratio is affected by world events such as war. The effect is evidenced in the decline in the sex ratio of 3.7 to 7.1% in the US Japan Austria and Germany following World War II. Another impact on male differentials is the discriminatory treatment of women in developing countries. The 1989 Demographic Yearbook states the following sex ratios: China (1.074) India (1.066) Pakistan (1.105) Bangladesh (1.064) Sri Lanka (1.040; 1.082 in 1970) Egypt (1.047) and the western region of Asia (1.06). Mortality rates are higher for females at all ages and may not necessarily be due to sex differentiated biomedical factors at all ages and may not necessarily be due to sex differentiated biomedical factors such as maternal deaths or tuberculosis. Pravin Visaria attributes the higher male ratio in India to unusually high female mortality rates since 1931. A comparison for 1982-84 supports this view and indicates variation between states. The reason given is traditional adverse discriminatory treatment of females. The preliminary results of the 1991 Indian Census report a ratio of 1.077 or a 6/1000 increase in 10 years. In Punjab villages in India and the Matlab project area of Bangladesh female disadvantage begins in the latter part of the 1st year when breast-feeding supplementation begins. Better health care for males is considered another factor affecting the disadvantage. The lower regard for females is expressed in the 2nd daughter having a 50% higher death rate than sons. An estimate of the magnitude of the problem of a high male ratio is given for china India Pakistan Bangladesh Nepal West Asia and Egypt. The total is 60-100 million missing females.