The Birth Gap Trap
There is no fast option to reverse the effects of a sustained Birth Gap. By its nature, an increase in the child birth rate today would take at least two decades before any benefit is felt, when newborns grow into working adults. During those two decades, society will in fact carry an additional burden of having to nurture and school the increase in children; more kindergartens will be needed, schools will have to be rebuilt, teachers and healthcare workers paid for, etc. Ironically, having larger families, may make it more difficult for working parents to work as much in the future or even work at all.
The Birth Gap Spiral
Yet, without increasing birth rate to reduce the Birth Gap, a nation’s problems will only get worse. With fewer children being born, that means fewer future potential mothers are being born (and fathers too of course, but mothers are what matter here). With fewer and fewer potential mothers being born with every generation, a population will spiral downwards. The option to stabilize the population always exists, by each person having 2.1 children (let’s just call it 2), but after a population falls sharply, the newly stabilized population will need to adjust to the consequences of what they have inherited: the national debt of the parents, grand-parents and beyond, and the need to look after the vast numbers of elderly relatives in terms of pensions and healthcare. As a number of authors have noted, there are no examples of any society throughout history that has managed to survive such a negative birth rate as we are seeing across Europe today.
Think of a parent in Germany today, where the Fertility Rate in 2015 was 1.2 children per family. (Fertility Rate can be a very dangerous measure to use for population statistics, but is valid in the example here where we look at families and not entire populations.) The graphic below illustrates that each person needs to have 1 daughter, on average, for a population to maintain stability (and yes, of course also one son, but its women that matter here as they are the future mothers). In a stable population, in simple terms, a person with 1 daughter would go on, on average, to have 2 granddaughters, 4 great-granddaughters, and 8 great-great-granddaughters. However, in a population with a sustained Fertility Rate of 1.2, things look very different. In simple terms, a person will have 0.6 daughters, 0.72 granddaughters, 0.86 great-granddaughters, and 1.04 great-great-granddaughters. Within four generations, a country like Germany, unless its Fertility Rate increases, would have 1/8th of the great-great-grandchildren needed by have a stable population. And it only gets worse from there.
The Birth Gap Burden
Now, let’s think of a great-great-granddaughter (or great-great-grandson), and how many relatives they might have to support. In such a world, its very likely they would have no siblings, nor aunts and uncles, nor cousins. Even second cousins would be rare. Yet they will have many aging relatives to help look after, either directly, or indirectly via taxation and welfare contributions. Working back up the pyramid, there will be grandparents, great-grandparents, and perhaps surviving great-great-grandparents to look after. By contrast in a stable population, this burden is shared by many other siblings and cousins.