Insurance: combined ratio, not EBIT

Insurance companies separate underwriting income from investment income. Combined ratio (loss ratio plus expense ratio) measures underwriting profitability. A combined ratio under 100 means the underwriting business is profitable before investment income[NAIC].

The combined ratio

Combined ratio = Loss ratio + Expense ratio
Loss ratio    = Incurred losses / Earned premium
Expense ratio = Underwriting expenses / Earned premium

Underwriting income vs investment income

A P&C insurer with a 95 combined ratio earned 5 cents of underwriting profit on every dollar of premium. The investment-income leg (float invested in fixed income) is reported separately and is what made Berkshire what it is. Adding the two gives pre-tax income but does not produce a meaningful EBIT.

When EBIT-style analysis still fits

See banks and REITs.