Abstract
Population aging is a phenomenon that has characterized most countries in the world for many years now. Also, for some time now, the literature has shown some social and economic impacts of this phenomenon. This chapter intends to address an impact of a social nature, namely gender inequality, and an impact of an economic nature, namely the global burden of diseases, to which the literature on population aging has not yet given the necessary attention. For these impacts it is important to distinguish healthy aging from unhealthy aging. In fact, healthy aging not only reduces the global burden of disease but also contributes to a reduction in gender inequalities with regard to quality-adjusted years of life.
TopIntroduction
In very general terms, it can be said that the phenomenon of aging has become more evident since the end of the Second World War. The gains in life expectancy, associated with a generalized decrease in birth rates – with the exception of the so-called «baby boom», which took place from the late 1940s to the early 1960s – profoundly changed the usual pyramidal format – so usual that the very name of the figure indicates that – of the population pyramid, for an inverted U-shape, or even for an urn-shape,1 particularly in certain countries.
Figure 1 shows how has life expectancy evolved over the most recent years across (almost all) countries around the world.2 Its visualization confirms that, in global terms, life expectancy at birth (LEB) has been gradually increasing, currently standing at around 73 years of age. In addition, it also shows that the dispersion in the values of this variable has been decreasing, albeit in a somewhat tenuous way. Still, there is a persistent bias to the left of the value distribution, i.e. a larger tail associated with lower LEB values.
Figure 1. Box-plots for Life Expectancy, at birth in the world
This aging is associated with the fourth phase of the so-called demographic transition model, which characterizes many countries for having low mortality rates and low birth rates.3 According to this model, the socio-economic development that countries are experiencing results in a shift from high birth and death rates (phase 1) to low birth and death rates (phase 4). Thus, it is not surprising that, even today, underdeveloped countries can be characterized by being in phase 1 or, at most, in phase 2 (high birth rates and mortality rates decreasing rapidly).
This also means that it is to be expected that Figure 1 does not allow to disclose the differences that will certainly exist if the data for life expectancy at birth are broken down, according to the level of development of each country. Being true that some countries are exceptions to the rule, as is known, the different continents present, in general terms, different levels of development. Thus, in order to clarify the eventual differences in the evolution of life expectancy at birth, across different continents, consider Figure 2.
Naturally, with all the care that is required, since it is acknowledged that the continents are heterogeneous groups of countries – see the cases of the Americas and Oceania, which Figure 2 itself highlights – it can certainly be said that the growing trend in life expectancy at birth is common to all continents, but its value is (considerably) different, with Europe, on the top, and Africa, on the bottom of the values for the LEB.
Figure 2. Box-plots for Life Expectancy, at birth, by continents
As is well known, population aging has several impacts of socio-economic nature (Yenilmez, 2015).4 With regard to these diverse natures of the impact of aging, the literature has not paid due attention to the crucial differences, from a social and economic point of view, of aging being a synonymous of living longer, being healthy or being sick by diseases (usually associated with older ages). To clarify, what is wanted to be said is that this chapter does not consider only important, from an economic point of view, the issue of increased health expenditure associated with population aging (Gerdtham, 1993), regardless of whether this happens in healthy or unhealthy terms, just as it does not consider it only important, from a social point of view, population aging, regardless of whether it concerns the female or male gender (Restrepo & Rozental, 1994).
Key Terms in this Chapter
DALY: An acronym for Disability-Adjusted Life Year. It is an indicator that intends to measure the potential years of life that are lost as a result of premature death, or that will be lived with a deteriorated state of health, i.e., with a lower quality of life. Thus, 1 DALY represents 1 lost year of healthy life. By definition, a DALY results from the sum of two indicators: YLL and YLD (defined below). See also https://en.wikipedia.org/wiki/Disability-adjusted_life_year ; accessed on February 02, 2021.
YLL: Initials for Years of Life Lost. It is an indicator of mortality, i.e., for the number of years that are lost when dying younger than expected (premature/early death).
Life Expectancy at Birth: The average number of years that a newborn can be expected to live, assuming that age-specific mortality levels remain constant. Life expectancy at birth is extremely influenced by high levels of infant mortality and therefore may be not so much informative about the survival of adults.
HALE: An acronym for Health-Adjusted Life Expectancy. It is an indicator that aims to measure the importance of disability on life expectancy. Thus, life expectancy is adjusted by subtracting a factor that represents the number of years lived with a disability, which is weighted by a certain weight associated with that disability. See also https://en.wikipedia.org/wiki/Healthy_Life_Years ; accessed on February 02, 2021.
YLD: Initials for Years Lived with a Disability. It is an indicator of morbidity, i.e., for the burden of living with a disease or disability, which diminishes the quality of life.
QALY: An acronym for Quality-Adjusted Life Year. It is an indicator that aims to measure the years of life (already lived or expected to live) adjusted by the quality of life associated with a given health condition. Thus, 1 QALY represents one year of life in perfect health, assuming, at the other extreme, that it will be 0 at the time of death. See also https://en.wikipedia.org/wiki/Quality-adjusted_life_year ; accessed on February 02, 2021.
Life Expectancy at 60/65: The average number of years that a person at 60/65 can be expected to live, assuming that age-specific mortality levels remain constant. Plainly, this is a better estimate of survival within the adult life course than life expectancy at birth, particularly for low-income countries, in which high levels of infant mortality exist.