To quantify the impact of this policy change, RMS said it reviewed the historical record to determine the long-term potential for multiple damaging hurricanes hitting the state in one season--a phenomenon called hurricane clustering.

"When clustering occurs, it is possible for one home to be hit by more than one hurricane, as was the case for some properties last season. In this case, a seasonal deductible will result in higher insurance claims relative to a single-event deductible," said Kyle Beatty, meteorologist at RMS.

However, he said an RMS simulation covering "over one million years of hurricane activity shows that this is extremely rare. The majority of risk is driven by years when a location is impacted by only one storm."

The impact of the new legislation on hurricane insurance risk varies based on the size of the deductible in force and the location of the property. The impact is greatest in areas of high hurricane frequency, such as Southeast Florida, and for policies with high deductibles.

Commercial and multi-location policies with blanket deductibles would experience different effects, and are not addressed under the new legislation.

RMS said its analysis of seasonal deductibles is part of a comprehensive research initiative it launched in November 2004 to analyze the unprecedented level of data generated by the 2004 Atlantic Hurricane Season. The program includes research into hurricane frequency and an extensive analysis of industry claims data.