LOOKING at demographic trends is usually about as exciting as watching chess -- but Ireland's turbo-charged population explosion makes the demographic trends here resemble Formula One. Our relish for making babies, the influx of foreigners and new longevity of our older citizens are all conspiring to accelerate population growth at rates seldom seen outside Africa and Asia.

Yesterday's release of preliminary figures from this year's census caught out the experts, who had assumed that all these trends were moderating quickly. To be sure, there are some signs of a slowdown but with a population just shy of 4.6 million, we now have slightly over 340,000 more people than five years ago. This is around 100,000 more than many demographers had predicted.

It is as if the Government unexpectedly discovered the equivalent of the entire population of Co Kilkenny hiding underneath its bed.

While this is good news for the individuals involved, it presents a formidable challenge to Government and the planners, who must cope with our exuberant lust for life, as well as foreign workers' continued interest in living here.

Schools and old people's homes will have to be built, while the perhaps surprising reluctance of people to emigrate will place further strains on the welfare system.

The fact that our population is now bigger than we thought means the Government will have even less money than had been expected to spend on meeting the needs of each inhabitant in the years ahead.

It also means that the 2008-2010 recession was worse than had previously been calculated because the larger population should have boosted everything, from retail sales to tax revenues.

The fragility of the economy and the unreliability of official economic forecasts have been highlighted once again.

Ireland is a very unusual country by European standards.

The average annual growth rate of 1.6pc over the 2006-2011 period was four times faster than the European Union as a whole and almost twice as strong as the rate in the US.

While these figures are stark, the number of new children is what really differentiates us from the rest of Europe.

Newborns have boosted the population by around 1.1pc a year over the past few years. The average across the rest of Europe is around 0.1pc, with the rest of their growth coming from immigrants and people living longer lives.

It is our fondness for procreation that prompted Eurostat to forecast earlier this month that the population would jump 48pc to 6.5 million over the next half-century, while many other countries will see their populations shrink.

Still, we have a long way to go before hitting 19th-century levels. The island now has just 6.4m inhabitants, compared to pre-Famine levels of 8.2m.

While our population is expanding rapidly, we remain the only country in Europe that has a significantly smaller population than 100 years ago, suggesting that the Famine had a far bigger impact on Ireland than two world wars had on mainland Europe.

So what sort of snapshot of Ireland in 2011 can be gleaned from the latest figures?

We now know that there are fewer ghost estates than had been feared -- but there are very significant numbers of vacant houses all along the Western seaboard.

With almost a third of houses vacant in Leitrim and more than a quarter in Donegal and Kerry, there is clearly no chance of price stabilisation in many places there for the foreseeable future.

Perhaps the most startling trend is the acceleration in suburbanisation.

As high oil prices and an ageing population encourage many people in the rest of Europe to move away from the countryside, we are continuing to see precisely the opposite trend.

The nation's cities are being emptied while their hinterlands are swelling at record rates.

Cork and especially Limerick have seen their populations shrink since 2006 as people flee to neighbouring counties, which have more space and cheaper houses.

Many parts of Dublin have also shrunk, despite the growth everywhere else.

Urban flight has been going on in the US for years. The social consequences for those left behind are well known and can often be catastrophic.

What slowly starts as a trickle can quickly become a flood as those who remained in old neighbourhoods fear that their homes will lose all value if they hesitate any longer.

The flight from inner-city areas here is close to an epidemic in some areas.

The Galvone B electoral district in Limerick has seen 44pc of the population leave in just four years.

In Dublin's Mountjoy B district, the population has shrunk by 22pc. All of the 10 biggest decreases among electoral areas recorded are in urban areas.

WE knew that Dublin's surrounding counties were swelling but the scale and speed of the cities' depopulation is startling. We are still in the middle of a process which will almost inevitably end in duller cities, blighted by decay, that close down at night as people go out closer to home in revitalised suburbs with fresh and interesting clusters of pubs and clubs.

This is not to say that some suburban areas won't be blighted by the same decay. What was once rural Balbriggan in north Co Dublin is the country's fastest-growing electoral division, enduring a population explosion of 58pc over the past four years.

That this has been allowed to happen is worthy of further investigation. No area should ever have to endure such an increase in such a short period of time -- it is quite simply unfair on the existing residents and on those who have moved in.

The other part of the country that has unperformed by almost every measure is Kerry. It is the county with the lowest population growth while Kerry's two large towns, Killarney and Tralee, have both seen significant declines.

It is too early to explain this strange under-performance by one of our most beautiful counties -- but it shows that our citizens are almost as reluctant to live in Kerry's splendid isolation as in the inner city.

Irish Independent