Most homeowners buying flood insurance do so only because it is required in areas considered most vulnerable to flooding, the study found. Just 20 percent of homeowners living in the most flood-prone areas buy federal flood insurance when they are not required to do so, the study says.
"Substantial flood damage from Hurricane Katrina was suffered by homes located in flood zones whose owners were not required to purchase flood insurance," said Lloyd Dixon, lead author of the report.
Only about 1 percent of Americans living outside flood zones buy federal flood insurance, according to the study, even though they sometimes become flood victims as well.
Fifty to 60 percent of the 3.6 million single-family homes in the most flood-prone areas are required by law to buy federal flood insurance. But the owners of the remaining homes in the most flood-prone areas and the roughly 76 million single-family homes in the nation outside these areas are not required to buy flood insurance.
The study is part of a wide-ranging evaluation of the nation's flood insurance system that was requested by the FEMA and coordinated by American Institutes for Research (AIR). AIR is an independent, nonpartisan not-for-profit organization that conducts behavioral and social science research on important social issues and delivers technical assistance both domestically and internationally in the areas of health, education, and workforce productivity.
"The findings represent important new information that contributes to the larger effort to improve the flood insurance program," said Marc Shapiro, AIR's director of the evaluation project. Additional studies and the final AIR report will be released later this year.
The RAND study also found little evidence to suggest that increasing the number of homeowners who buy flood insurance would lower FEMA disaster assistance to individuals following floods. The lack of relationship is partly because flood insurance does not cover temporary housing assistance, which accounts for roughly 60 percent of FEMA individual assistance following flooding disasters. The FEMA individual disaster assistance program is one of many forms of federal disaster assistance available to individuals, businesses, and governments following floods.
Extending the National Flood Insurance Program to include temporary housing could help reduce FEMA individual disaster assistance payments, according to the report, although such a policy change would require a broader examination of potential impacts.
The RAND study also explores the number, location and characteristics of homeowners who purchase federal flood insurance. In addition, it outlines what motivates people to buy insurance and assesses the implications of increasing sales of flood insurance.
The analysis provides a solid basis for policymakers to determine the National Flood Insurance Program's impact, assess costs and benefits, and evaluate proposed reforms, Dixon said. For example, the findings provide the data needed to better estimate the effects of recent proposals to extend the mandatory purchase requirement to all homes in Special Flood Hazard Areas.
The RAND study also found that:
* Flood insurance purchase rates are much lower in communities that have a relatively small number of homes in a floodplain or that have a low proportion of homes in a floodplain. The disparity may be because insurers market flood insurance less aggressively in communities with fewer homes in the floodplain or because there are fewer insurance agents famil