# Stretched Exponential Survival Analysis for South Korean Females
## 3 Results and Discussion
### Discussion  
Now, it is noteworthy that the stretched exponential survival analysis enables the quantitative and comparative study of female lifespan between South Korea and other countries, particularly quantifying the survival rate, the characteristic life, and the maximum lifespan. All evidence  
Figure 4: Estimation of the maximum lifespan and the characteristic life for Korean female (data from the Korean Statistical Information Service, [[http://kosis.kr/eng](http://kosis.kr/eng)]([http://kosis.kr/eng](http://kosis.kr/eng))). The maximum lifespan gradually decreases at a constant rate of \(\sim\)2.99 years per decade and the characteristic life gradually increases at a constant rate of \(\sim\)3.30 years per decade. suggests that South Korea has a remarkable rapid increase in female lifespan during the three recent decades (from 1987 to 2016), as demonstrated from the characteristic life analysis in Figures 2 and 3. An interesting question is why South Korea exhibits the highest increase rate in female lifespan. Economic development in South Korea is supposed to be beneficial to health care improvement, presumably provoking many potential social or cultural changes that are favorable for healthy daily habits and welfare. Obviously, health is the result of a combination of individual, social, and environmental factors [20]. In general, the recent increase in the numbers of older people in developed countries is a consequence of advances in hygiene and biomedicine as well as an artefact of human civilization [21]. In particular, South Korea has experienced rapid economic development and a substantial increase in life expectancy in an extremely short period, between 1970 and 2010, mainly due to the rapid processes of industrialization and urbanization [22; 23]. Specifically, South Korea is expected to become the first country where the life expectancy at birth will exceed 90 years for women [24]. The recent industrialization and the subsequent improvements in living standards, nutrition, and health care have often been cited as major contributions to the remarkable improvements in health for South Korea [25]. The rapid increases in life expectancy in South Korea could be mostly achieved by reductions in infant mortality and in decreases related to infections and blood pressure [25]. More recent gains in South Korea have been largely due to postponement of death from chronic diseases [25]. These gains were mainly due to broad-based inclusive improvements in economic status and social capital (including education), which improved childhood and adolescent nutrition [26], expanded access to primary and secondary health care, and facilitated rapid scale-up of new medical technologies [25]. South Korea has also maintained lower body-mass index and blood pressure than other industrialized countries [27; 28], and lower smoking in women. Additionally, South Korea might have lower health inequalities (for cancer and cardiovascular disease mortality, and for self-reported health status) than some of their western counterparts, especially for women [24; 29; 30]. The death rates from all causes in South Korea decreased significantly in both genders in the last three decades except for a period following the economic crisis in the late 1990s [31]. Looking at the trends in infectious disease mortality for South Korea, 1983\(-\)2015, infant mortality caused by infectious diseases has substantially decreased, while death rates from infectious disease for elderly populations with lower education levels and subgroups susceptible to respiratory infections and sepsis has not decreased overall [32]. The potential reasons for South Korea may be plausible but not for other countries. Finally, the lifespan trends for Korean female may give a clue for the question regarding if there is a biological or social limit to human lifespan [3; 33; 34; 35; 36]. The heterogeneity in population and the dynamics of heterogeneous populations would become important in interpreting human lifespan [37; 38].