More and more young people find themselves without full-time jobs - relying on their parents or staying longer in school.
"We call this problem 'Young Adult Failure to Thrive Syndrome'," said population expert Vegard Skirbekk from Austria-based International Institute for Applied Systems Analysis (IIASA).
While the phenomenon had been recognised in individual countries - including Italy, France, Spain and Japan - explanations have often focused on recent causes such as government fiscal difficulties.
The study shows that failure to thrive can be traced to global economic and demographic shifts beginning in the 1980s.
The study finds that failure to thrive can be tied to three major economic factors worldwide.
First, an increasingly globalised labour force means that workers can move more easily between countries.
Second, education levels have soared around the world, meaning many more workers are available for skilled positions.
Third, more women have joined the labour force.
All these factors mean more competition for jobs, particularly for young people who have little practical experience.
In addition to changes in labour supply, technological changes have both created and destroyed jobs - with a trend towards fewer industrial jobs and more service sector jobs.
"These changes mean that even as economic conditions have improved for some in the population, young people are worse off today than they were 20 years ago," added IIASA researchers Warren Sanderson.
Such economic disadvantages also have an effect on fertility rates and family formation as many young people cannot afford to start families until later in life, said the study published in the Finnish Yearbook of Population Research.