No single method is perfect. Actuaries typically run multiple methods, compare the results, and select a point estimate —often the mean or a conservative (higher) estimate, such as the 75th percentile. The final reserve is critical for financial statements (Schedule P for statutory filings) and for calculating the insurer's surplus to ensure solvency.

A P&C insurer that excels at reserving but fails at ratemaking will be solvent but unprofitable—slowly bleeding surplus. An insurer that excels at ratemaking but fails at reserving will appear profitable until a wave of adverse development destroys its balance sheet overnight.

This text provides a concise, structured overview of the fundamentals of ratemaking and loss reserving in property and casualty (P&C) insurance. It’s aimed at actuaries, underwriters, risk managers, insurance students, and other professionals who need a practical introduction to pricing insurance products and establishing reserves for unpaid claims.