Analysts often apply asset-based valuation to natural resource companies. For example, a crude oil producer such as Petrobras (NYSE: PBR) might be valued on the basis of the market value of its current proven reserves in barrels of oil, minus a discount for estimated extraction costs. A forest industry company such as Weyerhaeuser (NYSE: WY)

might be valued on the basis of the board meters (or board feet) of timber it controls.

Today, however, fewer companies than in the past are involved only in natural resources extraction or production. For example, Occidental Petroleum (NYSE: OXY ) features petroleum in its name but also has substantial chemical manufacturing operations. For such cases, the total company might be valued as the sum of its divisions, with the natural resource division valued on the basis of its proven resources.