Much has been spoken and written regarding the demographic disaster most developed, modern countries in the West are currently facing, but the issue is an abstract one for most people and does not seem to garner too much concern. Rather than rattle on about the myriad of negative effects low birth rates and sub-replacement fertility phenomenon will surely cause in the near, mid, and long-term, or elaborate on the underlying reasons, I thought it might be interesting to simply illustrate the extent of population decline through the example of my own family beginning with my two sets of grandparents (whom I have labelled as great-grandparents) and working down from there. I am in the grandchildren generation.
One thing you should keep in mind as you glance at the figures below is this - replacement fertility is pegged at 2.1 children per woman, which is considered the absolute minimum to prevent social and economic decline.
Paternal great-grandparents 2
The paternal side of my family starts off fine. The great-grandparents had three children, which is above the 2.1 threshold. Their three children, one of which is my father, had a combined total of six offspring, which misses the replacement fertility mark by 0.6 if you total it. Though this is suboptimal, it is fairly close to what the bare minimum should be. Now, the "grandchildren" category have had a total of eight kids and it is unlikely anyone in that category will have any more. The replacement fertility number should be 12.6 children for those six individuals, yet my generation on the paternal side managed only 8, which is 4.6 fewer children than are required to maintain a stable population.
Unfortunately, the data on my maternal side is even grimmer.
Maternal great-grandparents 2
Once again, the "children" generation missed the replacement fertility level by a fraction, but at least they managed to have two offspring for every couple, but look at what has occurred after that. The "grandchildren" generation would have needed 16.8 offspring to maintain replacement fertility levels. On my maternal side, my seven cousins and I have managed three children between the eight of us, and more births are highly unlikely here. Essentially, my generation on the maternal side had 13.8 fewer offspring than would be required maintain healthy replacement levels. Think about that for a moment. 13.8 fewer children! That's a soccer team, for crying out loud!
The combined number of individuals in the "grandchildren" generation on both sides of my family equals fourteen. Their combined offspring in the "great-grandchildren" category totals eleven. My generation should have had nearly thirty children to maintain healthy fertility levels. Instead, we had eleven - barely more than a third of what is considered the minimum. If I have calculated this properly, this means that the fertility rate for my generation was a mere 1.2, or nearly half of what would have been required to maintain replacement levels in society!
1.2 rather than the minimum 2.1!
I must admit, that really hits home. What makes it all even more alarming is the knowledge that my family probably represents the norm in most Western countries.
Note: I am not a demographic statistician, so I may not have used the terms above correctly, but I believe the numbers are accurate all the same.