Last week I looked at the famous finance professor and fund manager Michael Mauboussin’s method for valuing companies. It’s the start of a series where I get into investing in a bit more detail. It’s good stuff, whether you’re serious about investing or not. I’m always impressed by how clearly people like Mauboussin think. You soon start applying their models to other contexts.   Mauboussin’s valuations boil down to four things: the return a company gets on its investments, what it pays for funding, how fast it’s growing, and the discount rate.  Expressed in this way, valuing companies sounds simple.…