摘要：Motivation. The goal of experience rating is to improve the equity of individual risk rates. The National Council on Compensation Insurance (NCCI) periodically reviews the performance of its Experience Rating Plan, and makes changes to the Plan as warranted by the results of such reviews. Method. NCCI recently completed an extended review of its Experience Rating (ER) Plan. NCCI Staff presented the results of its analyses at regular meetings of the NCCI Individual Risk Rating Working Group (IRRWG). The IRRWG, which is comprised of actuaries representing workers compensation insurers affiliated with NCCI, discussed and reviewed these analyses and the actuarial methodology underlying the ER Plan with NCCI staff. Results. Although no major changes had been made for many years, testing indicated that ER Plan performance was still generally good. The primary cause of deteriorating performance was the use of a fixed split point between primary and excess losses while average claim severity increased dramatically. The review process uncovered many interesting facets of actuarial methodology related to experience rating, but the changes coming out of the review did not fundamentally change the structure of the plan. NCCI has implemented an increase in the split point from $5,000 to $15,000+ inflation (over three years), and subsequent procedures to periodically increase the split point in the future corresponding to an index of claim severity. Along with the split point increase, the maximum cap on modification factors was changed. As part of the review, NCCI also made changes to several components of the calculation of primary and excess experience period expected losses to conform to changes in NCCI’s class ratemaking procedures. Conclusions. A well-constructed experience rating plan can perform very well for a very long time with appropriate indexation applied to components. Simplicity, consistency, transparency, and an automatic indexation are particularly important for industry-wide bureau plans such as the NCCI Experience Rating Plan.
