Our recorded reserves represent management’s best estimate of the provision for unpaid claims as of the balance sheet date. We perform an actuarial reserve review for each product line and establish an actuarial central estimate at the review’s conclusion. The process to select the actuarial central estimate, when more than one estimate is available, may differ across product lines. For example, an actuary may base the central estimate on loss projections developed using an incurred loss development approach instead of a paid loss development approach when reported losses are viewed to be a more credible indication of the ultimate loss compared with paid losses. The availability of estimates by different projection techniques will depend upon the product line, the underwriting circumstances, and the maturity of the loss emergence. For a well-established product line with sufficient volume and history, the actuarial central estimate may be drawn from a weighting of paid and reported loss development and/or Bornhuetter-Ferguson methods. However, for a new long-tail product line for which we have limited data and experience or a rapidly growing line, the emerging loss experience may not have sufficient credibility to allow selection of loss development or Bornhuetter-Ferguson methods and reliance may be placed upon the expected loss ratio method until the experience matures.
While we believe that our reserve for unpaid losses and loss expenses at December 31, 2009, is adequate, new information or emerging trends that differ from our assumptions may lead to future development of losses and loss expenses significantly greater or less than the reserve provided, which could have a material effect on future operating results. As noted previously, our best estimate of required loss reserves for most portfolios is judgmentally selected for each origin year after considering the results from any number of reserving methods and is not a purely mechanical process. Therefore, it is difficult to convey, in a simple and quantitative manner, the impact that a change to a single assumption will have on our best estimate. In the examples below, we attempt to give an indication of the potential impact by isolating a single change for a specific reserving method that would be pertinent in establishing the best estimate for the product line described. We consider each of the following sensitivity analyses to represent a reasonably likely deviation in the underlying assumption.
cause a change of approximately $100 million, either positive or negative, for the projected net loss and loss expense reserves. This is relative to recorded net loss and loss expense reserves of approximately $1 billion.
Our ACE Bermuda operations write predominantly high excess liability coverage on an occurrence-first-reported basis (typically with attachment points in excess of $325 million and gross limits of up to $150 million) and D&O and other professional liability coverage on a claims-made basis (typically with attachment points in excess of $125 million and gross limits of up to $50 million). Due to the layer of exposure covered, the expected frequency for this book is very low. As a result of the low frequency/high severity nature of the book, a small difference in the actual vs. expected claim frequency, either positive or negative, could result in a material change to the projected ultimate loss if such change in claim frequency was related to a policy where close to maximum limits were deployed.
As a general rule, we also consider that equity securities in an unrealized loss position for twelve consecutive months are impaired.