Market notes · · 2 min read
Reserves move once a year, and in 2024 they moved $7.8bn
US liability reserves were corrected by $7.8bn in 2024. Why an annual correction leaves cedents and quota shares waiting a year to learn the number.
Reserves are an estimate, and insurers correct that estimate once a year. In 2024 the correction on US liability lines was $7.8bn.
That figure is calendar year adverse development: the amount by which the estimate for past claims had to be raised during the year. It came to about 1.5% of the reserves held at the start of the year, on Milliman's reading of NAIC annual statement data. (The NAIC is the body of US state insurance regulators, and insurers file these annual statements with it.) Narrow it to casualty, the liability side of insurance, and the figure is $15.8bn, 5.9%. Other liability occurrence on its own, the cover triggered by when a loss happened rather than when it was reported, is $10.0bn, 6.6%.
The size matters less than the rhythm
For a cedent, the insurer that passes part of its risk to a reinsurer, the mechanic underneath matters more than the size. IBNR, the reserve an insurer sets aside for claims that have happened but have not been reported yet, sits at one value for twelve months. The capital behind it stays committed at that value, which means it is tied up and cannot be used elsewhere while the estimate stands. Then the annual study lands, the number moves, and everything that was priced against it was priced against the old one.
Think of a fuel gauge that refreshes once a year. You can plan a long trip with it, provided you accept that the reading is already a little old when you look at it.
What a quota share inherits
A quota share is a treaty in which the reinsurer takes an agreed percentage of a book of policies, premiums and claims alike. It inherits the same rhythm. Both sides agree a figure, then wait a year to learn how wrong it was. The estimate can be reasonable on the day it is made and still get corrected later, and the treaty carries on in the meantime.
Where we work on it
We work on this part of the mechanics at NextBlock RWA: valuation produced continuously by Wavenure, our proprietary engine, published as it changes rather than arriving once a year with the study.
In plain words
Insurers estimate what claims from past years will cost, and they revisit that estimate about once a year. Anyone who priced a deal on the old estimate finds out afterwards how far off it was. Publishing the estimate as it changes lets the drift show up while it happens.
Information only. Not an offer or solicitation.