Almost half of Europe’s young adults are living with their parents, new data suggests – a record level of dependency that has sobering social and demographic implications for the continent.

One of the most comprehensive social surveys of 28 European countries revealed yesterday that the percentage of people aged 18-30 living with their parents had risen to 48 per cent, or 36.7 million people, by 2011, in tandem with levels of deprivation and unemployment that surged during five years of economic crisis.

The data from EU agency Eurofound shows that few countries are immune and that the phenomenon is not exclusive to the debt-laden Mediterranean rim.

The figures show large rises in the number of stay-at-home twenty-somethings in countries such as Sweden, Denmark, France, Belgium and Austria. In Italy, nearly four-fifths (79 per cent) of young adults were living with their parents.

However, Germany, the Netherlands, Ireland and the United Kingdom saw decreases in their numbers over that period. In Britain, the figure fell from 30 per cent to 26 per cent.

One of the report’s authors, Anna Ludwinek, said: “The situation of youth has really fundamentally changed. And it looks different from the situation of their parents and grandparents.

“It’s not only the world of work that has changed but society is changing, so the transitions are becoming much more unpredictable; people are not having a job for life or live in one place for life.”

She said it was a myth that living with children and parents in a multi-generational household was always a positive experience.

“Really we see that multi-generational households have very low life satisfaction and a very high level of deprivation and perceived social exclusion,” she said.

“One could argue that if you are at the age of 30 and are still living with your parents and, on top of that you have your own family, it is really difficult to start an independent life.”

The data underscores the predicament of “Generation Y”. Better educated than their forebears, they are condemned nonetheless to dimmer prospects than their parents’ generation.

The growing phenomenon of adults stuck living in their childhood bedrooms has, moreover, raised concerns about birth rates and demographics in an ageing continent.

The trend for parental dependency, the report’s authors say, cannot be solely explained by increases in the number of people studying later into their life, as millions more 25- to 29-year-olds have also been found to be living with their parents.

For women aged 25-29, this figure rose by five points to 26 per cent, while the proportion for men is up three points to 34 per cent. Even among those who have a job, the overall figure rose one point to 34 per cent.