With the daily focus on European crisis and the hope of central bank intervention, one of the essential features of the investment climate – at least for long-term investors – is easy to lose in the shuffle. That feature is valuation. It’s an easy concern to overlook, because with corporate profit margins close to 70% above historical norms (largely because of unsustainably large government deficits coupled with low private savings rates – see Too Little to Lock In), Wall Street is quite happy to look at the ratio of prices to near-term earnings estimates and conclude that valuations are satisfactory. But stocks are not a claim on one year of earnings. They are a claim on a very long stream of cash flows that will actually be delivered into the hands of investors. Unfortunately, the conclusion that stocks are appropriately valued rests on the implicit assumption that profit margins will remain elevated into the indefinite future.