You've heard of 'baby booms', but have you heard of 'baby busts'?
Despite a significant decline in birth rates in many countries across the world in recent decades, 'baby bust' is a term that hasn't caught on. As Ireland is now recording its lowest birth rate in history - and the rate continues to fall - it is one that might start catching on here.
As the accompanying graphic shows, and according to stats from the Central Statistics Office, the numbers of babies born relative to the total population is now at its lowest level in the 155 years since records began. As with much else around Ireland's demographics, the recent trend is somewhat surprising.
Over decades in Ireland, good economic times have made people more inclined to have kids. Slumps have done the opposite.
That was to be seen in 1980s, when the Irish birth rate very suddenly started to fall. That coincided with the beginning of miserable economic times.
The "long 1980s" only really ended with the arrival of the Celtic Tiger in the mid-1990s. The change in the country's economic fortunes then led to an immediate and substantial change in baby numbers. From 1995, the birth rate rose. Although it never recovered to the levels of the 1970s and before, the change coincided perfectly with the arrival of boom times. The rate continued to rise until 2008.
When the economic boom ended in tears, the baby boom went into reverse. Tougher times and greater uncertainty had, at the very least, some influence on people's decisions to bring more children into the world.
But here's what's surprising: since the economy turned around in 2012-13, there has been no change in the downward trend in the birth rate. In 2017, the last year for which figures are available, just under 13 babies were born for every 1,000 people living in the country. That was down by a fifth on 2008 and below the previous nadir of the mid-1990s. From the limited data available on last year, it appears as if the decline continued into 2018, despite last year being the best for the economy in at least a decade.
With a long record in Ireland of more money leading to more babies, one might have expected the recovery in the economy to translate into a baby recovery. But it hasn't. This time, it seems, is different.
So has Ireland's birth rate really decoupled from the fortunes of the economy? The short answer is yes.
Before looking at that in more detail, it is worth saying that one of the reasons for a falling birth rate today is the baby bust of 1980-95.
While the birth rate is a good indication of what is happening to a country's demographics, the fertility rate is better. Rather than measuring the number of babies relative to the size of the population, as the birth rate does, the fertility rate measures the number of babies among woman of child-bearing age (15-49).
Because of the baby bust of 1980-95, there are now fewer women of childbearing age. So the fertility rate has fallen by less than the birth rate. But both are down considerably. What explains the big trend?
The most obvious explanation is that Irish family preferences are becoming more like peer countries - from unusually high birth and fertility rates compared to those countries, Ireland is moving closer to the rest of Europe.
One reason for this is that very young women have all but given up having kids. The decline in teenage pregnancies in Ireland has been marked, as it has been internationally. At the beginning of the last decade, there were two babies being born to every hundred teenagers in any given year. That has fallen by a massive two-thirds since.
More effective contraception is unquestionably part of the reason, but attitudes and aspirations probably matter more - far more 18 year olds today want to pursue their studies than push prams.
A related explanation for the wider decline in fertility, and one that could be more passing in nature, is the tendency of women today to have their children later than their mothers.
The average first-time mother is now in her early 30s. In 1980 women usually became mums for the first time in their mid-20s. If the number of babies women have over the course of their lives were to remain the same, the fertility rate could bounce back, but that doesn't look likely because more women are not having kids at all, either out of choice or because they don't get round to it.
But despite this story of decline, the Irish still rank highly in European baby league tables. Ireland's fertility rate - of 1.8 - was the third highest in 2016, just after France and Sweden.
This was quite a bit higher than less baby-inclined Mediterraneans - Greece (1.38), Italy (1.34) Portugal (1.36) and Spain (1.34). Fertility rates in other countries, such as Austria, Finland and Germany are not much higher. And unlike Ireland, these countries have had low levels of births for decades.
All of these rates are, however, below the so-called replacement rate of 2.1 children per woman which is needed to replace those who die.
These trends throughout Europe have spawned many fears of 'demographic crises' and 'pensions time-bombs'. The ageing of societies will undoubtedly create economic and societal problems and tensions.
For now, Ireland enjoys a relatively young population. Much of Europe does not. It'll be worth paying attention to how they tackle the challenges that will arise. Their demographic present may be our future.