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Akansha Singh and Laishram Ladusingh

Mortality research in several developed nations has not been restricted to differentials in life ex-
pectancy. The differentials in the distributions of deaths at different ages and dispersion measures of
mortality have also been analyzed in recent studies. Various dispersion measures have been proposed
and examined along with the life expectancy to show the sex, socio-economic, and educational dif-
ferences (Edwards and Tuljapurkar, 2005; Shkolnikov, Andreev, Zhang et al., 2011). As with the de-
clining mortality and improvement in life expectancy, deaths are postponed and concentrated at ad-
vanced ages. Studies indicate that there is a substantial negative correlation in life expectancy and
dispersion measures across time in most countries (Shkolnikov, Andreev, Zhang et al., 2011; Singh
and Ladusingh, 2013). The correlation is strong, but there are inconsistencies. Some countries, nota-
bly the United States, have a greater lifespan disparity than expected, even after achieving higher
levels of life expectancy (Edwards and Tuljapurkar, 2005). At a similar level of remaining life ex-
pectancy, some population subgroups are experiencing lower levels of lifespan variation than others.
The sex differentials in dispersion measures of mortality have been observed in several countries.
Most studies suggested that the female advantage is vigilant in the mean length of life and also ob-
served in dispersion measures of age at death. The dispersion measure, standard deviation of age at
death for ages 10 or older (S 10) among females is lower than that among males, which indicates a
smaller uncertainty in female’s life span (Edwards and Tuljapurkar, 2005). Female populations in
developed countries, like France and the United States, have a higher mean and modal age at death,
†
the age where most of the deaths are occurring (Kannisto, 2001). The measure of life disparity (e ) is
also a dispersion measure based on the distribution of deaths at different ages and is defined as the
average life years lost due to death. Females often have a lower life disparity than males in devel-
oped countries (Shkolnikov, Andreev, Zhang et al., 2011).
However, until now, studies focused on the difference in lifespan variation have been limited
to cross-sectional analyses (Vaupel, Zhang, and van Raalte, 2011) or changes over time (Shkolnikov,
Andreev, and Begun, 2003), as evident from the studies in the developed countries. These studies
provide evidence that females from the developed countries usually have a higher life expectancy
and a lower level of death dispersion than males, with some exceptions. No such studies are from
developing countries, including India, either to support or negate the phenomenon of death disper-
sion found in the developed countries. The mortality differentials by sex, in India, are mostly ana-
lyzed for life expectancy at birth. Furthermore, the sex differentials in life expectancy at birth are
often examined by mainly observing their time trends (Chaurasia, 2010). It is quite evident that the
sex differentials in life expectancy at birth are widening over the period in India, with significant
differentials by age as well (Canudas-Romo, Saikia, and Diamond-Smith, 2015).
With significant mortality decline in the past four decades, there is a need for a comprehensive
study that looks into the sex differentials in life expectancy at birth and death dispersion in India.
This study is an attempt to enrich research on the implication of enhancement in life expectancy on
the dispersion of deaths over time, in India. This study would also examine the sex differentials in
life expectancy at birth and dispersion measures of mortality for states of India to discover regional
differentials in dispersion measures of mortality in India. Studies on dispersion of deaths are con-
fined to examining the differences between countries and less focused on variations within the coun-
try (van Raalte, Martikainen, and Myrskyla, 2014). Hence, this study would provide an impor-
tant contribution to understand the sex differentials in the dispersion of deaths for subpopulations
within the country.
Before we describe our data sources, we first provide some brief information about India's life
expectancy and distribution of deaths since the 1970s, relevant to this study.

1.2 Brief Background about Life Expectancy in India
The life expectancy at birth in India increased from 49.7 years in 1970–1975 (RGI, 1984) to 66.1
years in 2006–2010 (RGI, 2012). The increase was smaller for males than for females. The female
life expectancy at birth was higher during the late 1990s to mid-2000s in all the states of India, whe-

International Journal of Population Studies | 2016, Volume 2, Issue 1 39