And is it news in the first place? The press in the North and South of the country has made much of the confusion among the political class who are not ready to accept this development as it goes against other predictions announcing a decrease in the population. No such decrease has taken place! The previous population perspectives by the Planning Bureau, Eurostat and the UNO all indicate an increase in the population in the medium term. The only new element here is the fact that this increase was under estimated. The raises a lot of questions: what are the causes of this increase and what are the challenges that these demographic changes will pose over the coming decades?*
The population in Belgium is expected to increase from 10.087 million in 2010 to 12.440 million in 2050, representing an annual increase of 0.4%. This predicted increase can be explained by three factors. Firstly, a slight increase in the birth rate due to a younger age structure and partly due to a higher fertility rate among foreign women. This stabilization of the under-twenty category is an advantage in the long-term but involves higher infrastructural costs in the interim period. Secondly, a rapid improvement in life-expectancy, which, though good news for everyone, means an increase in the number of elderly people. Finally, a higher level of international migration which can be partly explained by the expansion of the European Union over the last few years.
These developments should inform social and economic policy, but will not fundamentally detract from the principal trends, that is to say an irreversible ageing process which adds to the particularly unfavourable situation in Belgium.
What is important is less the development of the total population than that of the active population and its employment levels.
Moreover, Belgium is distinct from other Western countries due to serious deficiencies. It is far from reaching the Lisbon objectives: in fact instead of increasing, the employment level has recently decreased. Our country has the highest proportion of people living in a household in which nobody has a job (12.5%). The employment level among women is among the lowest in the EU and that of elderly workers is also one of the lowest in Europe: Only one in three people between 55 and 64 years of age are still actively in work.

These factors increase the challenges that ageing imposes on each country. It would be necessary to deal with the increase in non-working people, the ageing of the workforce and the problems of productivity. The increase in life-span implies greater expenditure on health spending. The increase in the number and duration of pensions raises the question of how they will be financed.
In short, having experienced the most favourable period of its history, demographic development in Belgium calls for specific policies in order to have an impact on individual and family behaviour and on those institutions responsible for guaranteeing inter and intra-generational solidarity.

See S. Feld, Éd. "Changes in age structures and active populations", Academia-Bruylant, 2008.