Question: What valuation metrics do you use?
Buffett: The appropriate multiple for a business compared to the S&P 500 depends on its return on equity and return on incremental invested capital. I wouldn’t look at a single valuation metric like relative P/E ratio. I don’t think price-to-earnings, price-to-book or price-to-sales ratios tell you very much. People want a formula, but it’s not that easy. To value something, you simply have to take its free cash flows from now until kingdom come and then discount them back to the present using an appropriate discount rate. All cash is equal. You just need to evaluate a business’s economic characteristics.
Source: BRK Annual Meeting 2002 Tilson Notes