The report by the United Nations Educational, Scientific and Cultural Organization, or UNESCO, outlines a vicious circle.  Rising poverty and malnutrition - one of the spinoffs of the global economic crisis - has prevented many children from attending school.  But that's only part of the problem, says Samer Al-Samarrai, one of the study's authors.

"Even when they're in school, their ability to concentrate and actively participate in lessons - the financial crisis has had a really big impact on that," said Samer Al-Samarrai. "But second of all, the crisis has really put national education budgets under substantial pressure."

The United Nations says 72 million children do not attend school.  Universal primary education by 2015  only five years from now - is one of the U.N.'s Millennium Development Goals.
During the past decade, progress has been made.  About 33 million more children now attend school than in 1999.  And many more children now complete primary school.