OREANDA-NEWS. In a new special report, 'U.S. Property/Casualty Insurer Reserve Experience - Reserve Risk Versus Performance', Fitch Ratings reviewed longer-term statutory loss reserve risk and development experience for a group of 40 of the largest U.S. P/C insurers.

U.S. property/casualty insurers have benefited from nearly a decade of stable loss costs and favorable reserve development. Still, loss reserve adequacy remains a key source of uncertainty and potential capital volatility for P/C insurers. Inadequate reserves are typically a major contributing factor in P/C insurer insolvencies.

Reserve analysis centers on assessing the adequacy of current balance sheet loss reserves. Insurer reserving prowess is shown over the longer term by the record of reported favorable or unfavorable prior-period reserve development. Demonstration of consistent loss reserve adequacy or redundancies is viewed favorably in the rating process.

Fitch's analysis revealed considerable differences in company reserving performance on an accident year and calendar year basis. While many companies reported long-term favorable development on average, a smaller group experienced average deficiencies.

The report compares reserve risk across this group of insurer's based on reserve volatility measures used in Fitch's Prism stochastic capital model as well as reserve mix by product segment, highlighting relative exposure to longer tail liabilities. Companies also have varying reserve leverage metrics, which influences the effect that changes in reserve estimates have on reported capital and surplus.

For the group, Fitch measured average annual reported reserve development since 2004 based on the change in accident year loss ratio from original estimates and calendar year reserve development as a percentage of total reserves. Companies with reserve profiles viewed as riskier due to a concentration in longer tail liability segments reported the most favorable reserve experience over the period, including: The Doctors Companies, Markel Corporation and Proassurance Corporation.

The full report U.S. Property/Casualty Insurer Reserve Experience - Reserve Risk Versus Performance' dated Feb. 19, 2015, is available at 'www.fitchratings.com' under 'Insurance' and 'Special Reports'.