1. Warren Buffett has learned that a consistently high return on total capital is indicative of a durable competitive advantage. He is looking for a consistent ROTC of 12% or better.
2. With banks and finance companies he looks at the return of total assets ROA to determine if the company is benefitting from some kind of durable competitive advantage. Warren Buffett looks for a consistent return on assets ROA in excess of 1% (anything over 1% is good, anything over 1.5% is fantastic) and a consistent ROE in excess of 12%.
3. In situations where the entire net worth of the company is paid out, creating a negative net worth, Warren Buffett has only made investments in those companies that show a consistent ROTC of 20% or more. The high ROTC is indicative of a durable competitive advantage.