While the world`s population will spiral towards the 9 billion mark by 2050, the industrial world is confronted with aging populations and in an increasing number of countries, dramatically shrinking population size, according to DPA.
According to the most recent United Nations` projections, the populations of 45 countries are expected to shrink between now and the year 2050.
Among them are countries like Japan, Germany, Italy and most countries in Central and Eastern Europe.
Within individual nations, write German researchers Benny Geys, Friedrich Heinemann and Alexander Kalb, there are also marked rural- urban disparities.
In Germany, even as relatively rural regions experience significant population drops, big cities are growing.
And they say there is a good a reason for this: It is harder for smaller towns to adjust, creating a downward vortex. The more people leave a small town, the more difficult it is for a small town to attract jobs and services. And that lack of jobs and services prompts more people to leave town.
The number of people in a smaller city may go down, but the costs of providing services remain fixed, resulting in a higher tax burden for those who remain.
`For municipalities up to a size of 6,000 inhabitants, the costs for providing public goods fall under-proportionally with population size,` the researchers write in their report. `As such, a significant strain on local public budgets is to be expected for these entities with population decline.`
Big cities have other problems, but not this particular problem, they say.
`In contrast, larger municipalities are less confronted with the fixed cost problems and should, therefore, be more able to cut costs in proportion with falling population,` the researchers say.
The result, in many parts of Europe at least, will be that big cities will continue to get bigger and small towns will get smaller and smaller.
`When municipalities in the rural areas find themselves in the population shrinkage-cost trap in the future, this tendency will accelerate. In this sense, large cities and agglomerations are likely to be the `winners` of demographic change,` the researchers say.
The researchers predict that Japan`s population will shrink by 20 per cent between now and 2050 from 127 million to just over 100 million.
Germany`s population will drop from 82 million to 74 million, down 10 per cent.
In Italy, the population will decrease by 7 per cent from 59 million to 54 million.
Hardest hit will be countries of the former Soviet Union and its neighbours. Bulgaria`s population will drop a whopping 35 per cent, with Ukraine, Russia, Moldova, Belarus and Romania experiencing similarly high decreases of between 25 and 35 per cent.