Back in April 2008, when Government statisticians last pondered the State’s long-term demographic future, unemployment stood at just 5 per cent. Alas, that happy state of affairs came to an end within months. The downturn the economy took over the following two years turned out to be much worse than even the most pessimistic souls envisaged.
In better times five years ago, the statisticians believed that the population of the 26 counties could surpass its pre-Famine peak of 6.5 million by the 2030s, and hit 7 million around 2040. They don't believe that any more.
Net migration
Along with everyone else, they underestimated the scale of the shock that was to befall the economy, and its knock-on effects for one of the main drivers of population growth over the previous decade and more: very strong net migration.
The biggest single change to the overall population projections over the coming decades is the return of the old scourge of emigration.
Before the crash, the projected annual numbers moving abroad was put at 20,000 all the way out to mid-century. Over the past four years, the figure has been four times higher, and the number crunchers at the CSO now expect outflows of the same magnitude to continue until 2016.
Over the rest of the period to 2046, their scenarios foresee 40,000 to 55,000 people leaving each year.
New arrivals
But it is not just a fall in the numbers expected to depart that has changed the overall projections; new arrival estimates have also changed quite radically. Although immigration since the crash has fallen back, there have still been around 50,000 new arrivals each year since 2010 – a surprisingly high number given the state of the jobs market.
Partly as a result, the statisticians have increased by half their projections for the numbers moving to the State each year in the decades to come.
Along with varying assumptions about mobility into and out of the country, different scenarios on fertility and longevity were used by the CSO to generate six separate paths for the population out to the middle of the 21st century.
Variety of scenarios
Under the strongest population growth scenario (see graphic) the Republic's population will reach 6.7 million in 2046, an increase of almost 50 per cent on today's 4.6 million.
Under the other five scenarios, the numbers living in the 26 counties in 2046 will remain below the peak registered before the Famine. If the lowest of the six scenarios comes to pass, the State will be only marginally more crowded in mid-century than it is now, with a population in 2046 of just under five million.
But that the population is expected to be higher in 33 years' time under all scenarios marks Ireland out from its peers, and others besides. In almost every rich country – and in a growing number of middle and low-income countries, too – the numbers of children being born is insufficient to replace the numbers dying.
Top of fertility league
Ireland is different. Irish women not only have more babies than anywhere else in Europe, they have enough children to ensure that the population replaces itself, even when migration effects are stripped out. Under all six CSO scenarios, Ireland will remain near the top of the fertility growth league in Europe in the decades to come.
There is good reason to believe this. The recession has more or less proved that bad economic times do not dampen the urge to reproduce in Ireland. In the four years since the crash, the birth rate has actually been higher than in the previous four years, which coincided with the height of bubble-era excess.
Golden years
Perhaps the best news from yesterday's report is the additional years of life that those alive today and future generations are expected to enjoy. As the second chart shows, both men and women in 2046 will, on average, make it to the second half of their 80s before shuffling off.
That said, it would be wrong to make too much of any of these projections, as the statisticians themselves caution against.
The world could change far more in the decades to come than Ireland has in the past five years.
Some scientists, for instance, believe that medical advances could allow decades rather than years of extra life, while some epidemiologists fear that if avian flu jumps species, the planet is in for a pandemic that will slash the global population.