"Spain is less attractive because there are no jobs, " Albert Esteve of the Barcelona Centre for Demographic Studies told Spain's National Radio.

BBC: Europe

Researchers from the Centre for Demographic Studies (Barcelona) and the Minnesota Population Centre have for the first time trawled through the censuses of more than 50 countries in every continent for people aged 25-39.

ECONOMIST: International marriage

So, digital studies started including demographic data.

FORBES: A Story About Occupying Digital Space. Or an Answer to 'How Should I Be Measuring Digital and Social Media Anyhow?'

The International Institute for Applied Systems Analysis in Austria studies the timing of demographic milestones and recognizes the inscrutable variables.

FORBES: Pro-Planet Is Pro-Choice

Faitelson's study, like the studies published since 2004 by the American-Israeli Demographic Research Group show that from a demographic perspective, Israel is in the same situation as many Western states today.

CENTERFORSECURITYPOLICY: Obama's diversionary tactics

Psychological studies show that images of babies engender positive emotions and empathy in most people and across cultural and demographic divides.

FORBES: How Do You Get A Billion Hits On YouTube?