In this chart Guy Carpenter is looking at the reserve cycle in a different way: by studying the booked ultimate loss by accident year. We choose accident year because actuaries typically analyze losses according to their year of accident. The estimate of the ultimate loss for a particular accident year ideally should not change over time if the initial estimate was correct. However, using U.S. industry data, we find that as a particular accident year is re-estimated periodically, a cycle appears.
