We perform internal loss reserve studies for all product lines at least once a year; the timing of such studies varies throughout the year. Additionally, each quarter for most product lines, we review the emergence of actual losses relative to expectations. If warranted from findings in loss emergence tests, we may alter the timing of our product line reserve studies.
Short-tail business generally describes product lines for which losses are typically known and paid shortly after the loss actually occurs. This would include, for example, most property, personal accident, aviation hull, and automobile physical damage policies that are written by ACE. There are some exceptions on certain product lines or events (e.g., major hurricanes) where the event has occurred, but the final settlement amount is highly uncertain and not known with certainty for a potentially lengthy period. Due to the short reporting and development pattern for these product lines, the uncertainty associated with our estimate of ultimate losses for any particular accident period diminishes relatively quickly as actual loss experience emerges. We typically assign credibility to methods that incorporate actual loss emergence, such as the paid and reported loss development and Bornhuetter-Ferguson methods, sooner than would be the case for long-tail lines at a similar stage of development for a given origin year. The reserving process for short-tail losses arising from catastrophic events typically involves an assessment by the claims department, in conjunction with underwriters and actuaries, of our exposure and estimated losses immediately following an event and then subsequent revisions of the estimated losses as our insureds provide updated actual loss information.
At December 31, 2010, net unpaid losses and loss expenses for the Global Reinsurance segment aggregated to $2.4 billion, consisting of $830 million of case reserves and $1.6 billion of IBNR. In comparison, at December 31, 2009, net unpaid losses and loss expenses for the Global Reinsurance segment aggregated to $2.4 billion, consisting of $788 million of case reserves and $1.6 billion of IBNR.
The fair value hierarchy gives the highest priority to quoted prices in active markets (Level 1 inputs) and the lowest priority to unobservable data (Level 3 inputs). Inputs in Level 1 are unadjusted quoted prices for identical assets or liabilities in active markets. Level 2 includes inputs other than quoted prices included within Level 1 that are observable for assets or liabilities either directly or indirectly. Level 2 inputs include, among other items, quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, and inputs other than quoted prices that are observable for the asset or liability such as interest rates and yield curves. Level 3 inputs are unobservable and reflect our judgments about assumptions that market participants would use in pricing an asset or liability. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. ACE makes decisions regarding the categorization of assets or liabilities within the valuation hierarchy based on the inputs used to determine respective fair values at the balance sheet date. Accordingly, transfers between levels within the valuation hierarchy are determined on the same basis.