The longer the region goes without an earthquake, the less likely Californians are to prepare for one. A 2006 Insurance Information Network of California study found that between 60 and 69 percent of respondents across the state said that they are not prepared for the threat of a mudslide (often a consequence of earthquakes) at their homes or businesses.The cost of earthquake insurance naturally plays a role in Californians' decisions not to buy coverage, especially in the current economic climate. A premium estimate for a 2,700-square-foot two-story wood home -- valued for insurance at $750,000 -- in the heart of San Francisco, a high-risk area, could be as high as $4,300 per year, and that's on top of a regular homeowners policy. "Whereas that same house in the Inland Empire, near L.A., say San Bernardino or Riverside, would be half that expense," says Moraga. The CEA has a premium estimator on its website.