The Future Population Health of the Industrialized Countries

The more developed countries are experiencing an inexorable decline with respect to population. Aging is reaching intolerable levels in the economy, both from the active (available workers) and the passive (e.g. health costs, pensions) point of view, redesigning a worrying scenario for the near future. On the other hand, fertility in many countries, and particularly in Italy, reaches such low levels that the prospects of a recovery, in terms of quantity, now seem impractical, unless of socio-demographic upheavals rather unlikely. In this context, most likely, from the point of view of demographic and social, he is starting a new era in which the main actors on the global stage will certainly be different from those in the field today, with completely obscure scenarios and still in the making. Surely, however, this situation has generated fears and concerns about the future of the population, especially for some signals that in the course of 2015 were recorded in Italy, such as the surge in mortality, especially with regard to older ages, where some observers have linked this phenomenon to a reduction in public spending in the health sector, a situation that would have penalized, certainly, the older age groups. On closer analysis, however, we realize that, precisely due to aging of the population of elderly, quotas have gradually increased, causing a swollen available to die, with the same probability of death.


Introduction
The more developed countries are experiencing an inexorable decline with respect to the population. Aging is reaching intolerable levels in the economy, both from the active (available workers) and the passive (e.g. health costs, pensions) point of view, redesigning a worrying scenario for the near future.

Some consideration about Italian population
The demographic structure of population of all developed countries, and especially that of Italy, has been shaped, as is stated in any book of demographic analysis, by the effect of great transformations that have powered the path of evolution in the twentieth century in general and since the end of the Second World War in particular.
Great structural movements that have characterized the evolution of the Italian population in the long term were initially that of the demographic transition, then the era of baby boom and finally the low-low fertility.
The demographic transition, 1 in fact, marks the passage of a population from an archaic development model, characterized essentially by high levels of fertility and mortality, a structure of particularly young age and a hierarchical disorder between parents and children [1] 2 (the latter dying before the former in large numbers) to a model of modern development, with values 10 of birth rates and death rates particularly low (and stable), a structure of much older age, and with the restoration of a more normal hierarchical order in the chronology of deaths between children and parents.
In the completion of the demographic transition process, the values of the quotients of natality and mortality pass from rather high levels, even around 40-60% to much lower values which, at the end of the process, can reach values even around 7-8% ( Figure 1 and Table 1, as regards Italy). This underlines a transformation of the vivacity of the natural movements: before the transition, the situation is characterized by many births and many premature deaths (with a large number of children deaths); after the transition, the situation is characterized by fewer births but with the lengthening of life span [2] due to the collapse of mortality in younger ages (known as infant mortality).
In case of the birth rate, the reduction process is uniquely determined by the inexorable reduction in births and by an important increase in procreation age of the mother (but also of 1 Scheme generalized by the trend of birth rates and death rates in the period of the demographic transition. 2 Livi Bacci, which emphasizes how this problem was actually at the base of the high birth rates. In essence, the couples (or families) produced more children in order to guarantee in the long term the survival of at least some of them, given the high level of mortality during childhood. the father) [3][4][5] 3 4 especially the "primiparous mother," whereas in case of the reduction path of mortality ratios and therefore mortality in general, there are many factors involved in its determination, because mortality is distributed in all age groups with a gradually increasing incidence.
The baby boom, however, which takes place temporarily at least in Italy around the end of the demographic transition process, is a typically Italian phenomenon. In this phenomenon, because of the contraction due to the traumatic effects of the Second World War, strong economic expansion of the 1960s is associated with a sharp increase in births such as to reach the point to return to pre-conflict levels, in the presence, however, of a period in which the mortality (especially infant mortality) lowering effect keeps alive a large number of births well beyond that found previously [2].  6 Source: our elaboration on ISTAT's data. 6 Figure loosely based on and adapted from Iaquinta [7]. 3 These concepts have already been widely anticipated and explored in numerous scientific papers, including, in particular, we point out P. Iaquinta-T. Traversa, Evoluzione della fecondità nelle società post-transizionali, the paper presented at the Giornate di Studio della Popolazione,   This effect made a high portion of births reach the adult age and hence it would be more appropriate to speak of living boom rather than baby boom; in fact, before the Second World War, about 30% of births did not reach the age of 5, in the 1960-1970s, this proportion already fell to about 3% [6], and in the future, thanks to the contribution of the infamous therapeutic interruption of pregnancy [7], it might fall very easily below 0.3-0.4%, reducing by hundred times the impact of mortality on the survival of the younger generations.
The great economic crisis of the Western world, which started at the beginning of the 1970s, constitutes actually the divide between an old and a new world, in which the powerful and extraordinary parameter of post-bellum development has to come to terms with a new world order.
Perhaps, for the first time, after the feast of progress and indiscriminate growth of the post-Second World War, the Western world is forced to come to terms with a new incumbent danger that hits it: the great oil crisis. This is a crisis, far from being just a purely economic one; in fact, it entails a reconsideration of the entire developed world, calling into question priorities and needs of the entire modern world.
To this situation, dramatic to some extent, countries react with a structural change which also involves the most basic units of social life, such as the family, featuring its new roles, its structure, and especially its composition.
It is at this point that takes shape in Italy the era of Low-Low Fertility [8], a time in which the level of fertility of Italian women reaches values which will not be in a position to ensure the replacement of generations (but similar events were experienced in France, Germany, and the Scandinavian countries).
The number of annual births in Italy precipitates from 1,016,000 births in 1964 to around 500,000 since the 1980s, inexorably sealing the fate of the Italian population in terms of both the reproductive capacity and the age structure, which is bound to have a lot of old people beyond any imagination.
Profound behavioral changes in the population, especially those quantitative ones, with respect to the demographic events, have an impact at easily recognizable intervals on the dynamic of labor market entry and exit, respectively, after 20 years in the case of entry and after 60 years in the case of exit.
This simple consideration opens new scenarios of the labor market: if it is true that in the 1960s there were births double those in the 1990s, roughly a quarter of a century later, these births (which, among other things, took place in the living boom era) will present themselves at the entrance of the world of work. Situation will be more regrettable when more or less after 30-35 years from this circumstance, these same generations will approach the exit threshold of the world of work, especially because the next generations born in the era of low-low fertility will not be so large as to ensure the replacement of those in exit.
This will highlight, in a short time, an irreversible condition: the number of people in exit will exceed by far that in entry into the labor market suffocated by the level of unemployment which these first five years of global economic crisis highlighted in a stringent way.

Labor market and demography
To evaluate the possible scenario for the next generations, in terms of world of work and employment recovery, a comparison between the generations of people willing to enter the labor market and those willing to exit from it was made to analyze what might happen in the near future as a result of the demographic changes that have characterized the Italian socioeconomic life after the Second World War.
To estimate the quantitative effects of the baby boom and low-low fertility on the population, two age groups temporarily willing to turnover were chosen, and a possible future scenario was built projecting the population data.
From the methodological point of view, the age groups relevant to this examination are that of 20-30 years willing to enter the labor market and that of 60-70 years willing to exit from it.
Then, a projection of the Italian population was made with the classic method, using as initial data the population enrolled in the registry office in 2016, the mortality table of 2012, the series of specific quotients of fertility by age of 2011.
The data used were derived from the official source (ISTAT) and were chosen because these were the most currently available in their specific nature, emphasizing that we are making hypothesis on evolutionary scenarios and approximations.
Also available are excellent forecasts built with self-modeling regression and moving average model (ARMA and ARIMA). Even though such models are precise and effective, these results, being available only in an aggregate form compared to the initial data, do not allow us to isolate the various components in order to assess the influence of any politico-social choice that  should be taken in the near future. In essence, therefore, the possibility to isolate the components of natality, mortality, and migration in the elaboration of projections allows us to make more probable assumptions about the future of the population itself. Table 1 and Figure 2 show the evolution of the number of births between the first quarter of the last century and the present day. Table 1 highlights the specific trend of the natality level, which affected and still continues to affect the social life in Italy.
Until the Second World War, the birth level was still maintained high in values consistently above the million births per year, with inevitable fluctuations due, in large part, to the approaching of the great crisis that would lead to disastrous conflict.
In any case, the last conflict represented a sort of "threshold value," a kind of divide between the old and the new world, also from the behavioral point of view in relation to the demographic events and to the reproductive process in particular.
In addition, the years after the Great War are also the years in which the reconstruction begins: Italy laboriously starts to develop and this goes at the same rate with great (demographic) achievements such as the sudden collapse of infant mortality.

Italian population projection
As mentioned, in order to properly estimate the structure of the Italian population in the coming years and, above all, in order to be able to isolate the components contextually involved in such a determination, it was chosen to make standard projections in an autonomous way so as to govern the individual variables and, eventually, assume alternative hypotheses on the individual components which interact in the formation of the future population.
In order to build the projections, the age structure of the population was derived from the official statistics ISTAT 2017, the latest available data [9]. The table of mortality, used to infer the survival rates [9], aimed to project the population in the next quinquennial age group, was available for 2010; the specific fertility [10] quotients by age were of 2011 (Tables 2a-c).
This heterogeneity of reference period must not be misleading in the projection framework, where the choices made are sufficiently aleatory and do not significantly affect the final data.
Rather, it should be clear that we are talking about future hypothesis, estimates, and, therefore, plausible (but certainly not real) values; one argument against it could rather be dictated by the fact that current indicators are largely used in referring to very variable demographic phenomena in order to estimate behaviors in the events of even 40 years ahead.
In any case, before going on, it would be better to underline some methodological limits of this technique, which may affect the results and, therefore, the indicators derived from them. It seems obvious that, while talking about projections of such a distant time (2061), at least 40% of the population living at that time is a population that still has to be born; a population that will inevitably bring with them habits, customs, traditions, and ideas that probably have not yet been formed in the current social and political scenarios. This could also mean a different way of facing problems, such as reproductive life, family, and social organization.
At present, moreover, the path of that idea of political unity of Europe would seem less likely: in fact, Europe is struggling to feel truly one people also because of the undeniable, great tradition that distinguishes the individual peoples of Europe.
Certainly, the emergence or not of a strong (social and/or political) movement of restoration of the autonomous economies or the definitive success of the European community project might make it necessary to rewrite the pages of history entirely different from one another, which, although not universally accepted, certainly influence the demographic behavior of the future generations.
A further consideration which is necessary before carrying out the analysis concerns the immigration component, which must not be confused with the foreign component among population (currently) residing in Italy.
More than 4,030,000 foreigners entered the register [11] on 31 December (equal to over 7% of the population): they are regularly included in these calculations and are sufficiently adapted to the behaviors of native population in order to considerably modify therein the future demographic behavior.
On the other hand, the focus here is on the immigrant component that powers our population with an annual balance of about 230,000 foreign nationals resident in Italy (280,000 registrations from abroad against 40,000 cancellations).
This part of the population, without considering that illegal immigration which is by its nature difficult to quantify (and moreover with all attempts to estimate since the 1980s, badly failed), could affect the final results of the projection, but precisely because of absolute randomness, it remains an absolutely uncontrolled portion on which it is more appropriate to make specific ad hoc comments.
Of course, as always, to put forward a hypothesis about values so distant in time may turn out to be a scientific quirk rather than a real possibility of analysis, because, in any case, any method utilized may return plausible values only, ignoring, de facto, possible major shifts in socio-demographic behavior of the population.
In any case, in light of these premises, the projection of the population was made under the assumption, as already mentioned, that it is closed and so made in the absence of migratory movements. This choice, not made randomly, really intends to answer the initial assumption, which turns out to be: what would happen to the future generations of workers if the population were projected as it is in the future?
That is, to be more precise, what situation would be created to the relationship between outgoing generations and incoming generations in the labor market, if this demographic situation persisted?
The analysis, then, was carried out by building quinquennial projections between 2016 and 2061, a time when the strength of the generations born in the baby boom (and living boom) era should have exhausted, and that at that date they should be really residual by then from the quantitative point of view.
The projections, built with the standard method, have been built for five-year periods, so they are available every five years from 2016 to 2061, but for the obvious need for space, only some significant years that are functional to the initial hypothesis are reported here.
Reaffirming once again the weakness of precision resulting from having fixed, inexorably, the law of mortality and the law of current fertility, under the assumption that they be unchanged for the next half century (not entirely appropriate assumption, but not too dissimilar from reality, except for some small correction factors), the results of elaboration return values open to interesting considerations.
First, the wave of those born in the baby boom era is now coming to the end of the race. In 2061, only very few representatives of this "era" will still be alive, leaving behind them much less consistent generations. These generations, although saved certainly by survival rates, 5 are, at the individual age, better than those that preceded them, will not be able to "replace" the generations of their predecessors. In simple terms, the Italian population is destined to decline The survival rate expresses in relative terms how many people belonging to the current age will reach the next one. In scientific terms: px = (L x+s )/L x .
substantially, starting already from the next few years with peaks of decline in the next two decades.
This situation is not only accompanied by the quantitative downsizing but will also reshape the population structure itself. In other words, the graphic representation of the population by age groups will hardly continue to be indicated as the "age pyramid" according to the data that will present themselves as a future scenario; it will rather have to be called the population "barrel" by age to reach, not so much time afterwards, the "inverted pyramid," where, for many years, (all those years for which the "baby-living-boom" lasted) the top of the graph will be much bigger than its bottom (despite in the presence of a slight recovery of women's fertility, which will, however, not be supported by an appropriate quantity of women available for procreation) [1]. 6  Source: our elaboration on ISTAT's data. Table 3. Percentage of population in age groups, Italy. 6 Basically, as stated, the fertility rate will return increasing values due to the mother "in late" fertility recovery (35 years old and more); but the total of women in the age group available to procreate will be more bounded in the previous group, nullifying the effects of the improvement in the procreation propensity.
To confirm what has just been mentioned above, it is enough to observe what is shown in Figures 2 and 3a and b, which draw the age "pyramids" of the Italian population in 2016, 2041 (i.e., a quarter of century later), and 2061 ( Figure 4, 45 years later) and in Tables 2a-c, which show the amount of the projections of the closed population, calculated from 2021 to 2061.

The health of industrialized populations
A major problem, which certainly will be faced in the coming decades, will be caused by the progressive aging of the population in all more developed countries and will reach very significant proportions particularly in Italy ( Table 3).
In Italy, for example, around 2050, more than a third of the population will be over 65-year-old and a third of these will be over 80 years.
An important consideration, however, is that despite the generations that will overlook the threshold of the 80 years from 2050 will come from generations born in the late twentieth century, when, then, they had already a culture of health, the knowledge that styles correct and adequate life can improve the quality of life, especially by the elderly, massive campaigns against smoking and use of drugs, certainly the frightening growth of older age groups will pose new structural limits to the population [12].
It is undeniable, in fact, that a large amount of pathologies that are spreading in recent years are closely related to age, and the growth of this will not only bring with it the growth and spread of diseases today marginal if not, indeed, unknown.
This lot will commit the future governance, on the identification of resources to cope with this situation and the migratory flows in the next few decades could be the key to restore vitality to a population particularly in trouble [13].