Reports of how poorly Americans are preparing for retirement have understated the problem because, in fact, the situation is getting worse, suggests a U.S. Securities Industry Association report released Tuesday.

The SIA reports that nearly half of U.S. households are not saving at all; and two thirds are not saving enough to retire adequately. “Americans are not saving enough for retirement,” said SIA president Marc Lackritz. “The SIA study more than confirms our worry — in fact, it points to reasons for growing concern that the housing boom is turning into a retirement bust.”

“This new data offer a far more realistic and, unfortunately, grim outlook than most previous forecasts,” added SIA chief economist Frank Fernandez. “The present savings behavior needs to dramatically change, and soon, if most Americans approaching retirement are to recover and save enough for retirement.”

The study pointed to the ‘wealth effect’ — that individuals save less as they perceive their net worth to increase — as a key contributor to the savings decline. It noted that the appreciation of housing prices generated a rise in net worth that is more broadly distributed than earlier increases driven by the equity market boom, which helped extend the wealth effect to lower income groups.

Other factors continue to hinder Americans’ abilities to save, including: higher fuel prices and rising interest payments eroding consumer purchasing power. Also, asset price inflation has come to a halt, at least for now, and the possibility that lower- and middle-income households can increase savings appears to be limited, it adds.

“As a result, it appears that roughly half of all baby boomers, the next wave of retirees, will be unable to maintain their standard of living in retirement, even if they postpone retirement. Also, down the road: if dissavings continues, as many as 20% of baby boomers will live in poverty after they reach 65 years of age, roughly double the number of impoverished seniors today,” the report warns

“The least prepared half of leading-edge boomers would need to mount a substantial and sustained saving effort now if they hope to avoid moderate to severe reductions in their standard of living after the age of 65,” said Fernandez, citing the SIA study. “For most, the likelihood of such a fundamental change in behavior seems improbable.”

The study found that for many Americans, almost 50% of their net worth is based on the value of their home; meanwhile, the number and percentage of households that owned a retirement account of any kind have fallen since 2001, it said. “Participation rates are declining and those who hold retirement accounts underutilize them,” it added.

“This is a critical time for American consumers to take control of their financial well-being in retirement,” said Lackritz. “The research we’ve conducted as well as other resources we have been developing, such as RetireSmarts.com, are meant to drive awareness of the retirement issue so that consumers, investors, policymakers and businesses can all work together to find viable solutions to the growing problem.”

The SIA’s new public education retirement Web site, www.RetireSmarts.com, is a resource on data, trends and statistical information for the retirement climate across the United States.