More than three quarters (78%) of retiring Americans may not be able to meet basic expenses for the remainder of their lives, and younger people may be facing an even bleaker financial future for their retirement years, says a new study from Brandeis University and Demos, a national public policy and research organization.

Single people and African-American and Latino households are the most economically vulnerable, according to the Senior Economic Security Index compiled by The Institute on Assets and Social Policy at Brandeis.

Some of the problems center on the fact that 45% of seniors pay one third of their income on housing and 31% have no equity in a home, 40% spend 15% on healthcare and one-third have no money left over after meeting essential expenses.

Even more alarming, says Tatjana Meschede, lead author of the study entitled, "Living Longer on Less: the New Economic (In)Security of Seniors, is what the findings mean for younger people.

"Today's seniors are better prepared for retirement than subsequent generations will be. They have benefited from pensions, jobs with significant retirement benefits and a stronger social safety net than subsequent generations will enjoy," Meschede warns.