Analysis of Residential Claims From the Northridge Earthquake Mary C. Comerio and John D. Landis for California Earthquake Authority

1996 Residential Recovery Study Zip code average insurance losses Zip code loss shares Claims by zip code Structural damage loss ratios by zip code Contents damage loss ratios by zip code

1996 Independent Variables Distance to the fault rupture plane Average peak ground acceleration Age of the structure Economic value of the housing Number of policy holders and amount of coverage

1996 Study Results POSITIVE Relation with Zip Code Losses –Average peak ground acceleration –Total number of policies NEGATIVE Relation with Zip Code Losses –Age of stock (i.e. housing built pre-1950) TECHNICALLY POSSIBLE TO PREDICT CLAIM RATES

PROPOSED CEA RESEARCH METHODS Sample 10% of policies with claims and policies without claims in zip codes with >100 claims after Northridge –Location –Coverage –Building Conditions –Claim Amount and Damage

1. Probability of Making a Claim Probability [policy holder i submitted claim] = f (distance of house to fault-rupture line; peak and average ground acceleration; soil conditions; deductible amount; policy type and coverage; home age; building type; design characteristics and condition; level and type of mitigation)

2. Estimating the Structural Damage Claim Amount Amount of Claim for Structural Damage = f (distance of house to fault-rupture line; peak and average ground acceleration; underlying soils conditions; policy type and coverage; home age; building type; design characteristics and condition; level and type of mitigation)

Summary of Research Tasks Map claim and non-claim policy holders in a GIS format Overlay with CDMG soil conditions Prepare a 2 stage logit and regression analysis of sub-system losses against relevant independent variables Analyze loss-reduction effects of mitigation if correlation exists