The chain ladder trusts the data entirely. The B-F method distrusts early data and blends an expected loss ratio (from pricing) with observed development. It is excellent for new, volatile accident years where paid data is sparse.
The successful actuary must be a historian, a mathematician, a forecaster, and a skeptic. They must respect the data but trust the process. They must balance the need for competitive pricing against the iron rule of solvency: never expose the company to a loss it cannot afford to pay. The chain ladder trusts the data entirely
A good actuarial practice uses from reserving to inform loss trend in ratemaking. For example, if the chain ladder shows medical claim costs are inflating at 7% per year, the pricing actuary builds a 7% annual trend factor into future rates. Part 5: Regulatory Environment and Standards P&C insurance is heavily regulated at the state level (in the US) or by national authorities (e.g., PRA in the UK, EIOPA in Europe). The successful actuary must be a historian, a