There’s an interesting debate raging between Michael Arrington of TechCrunch and Glen Kelman of Redfin about what it takes to build the next Silicon Valley and whether or not a major research institute is required to feed the entrepreneurial pipeline. You can debate the merits of each argument but think that they’re arguing over something of a moot point. I do think there is something very special about the entrepreneurial environment here. But I don’t think you can pin it down to just one thing. I asked one client the other day, a serial entrepreneur who asked to remain off the record (tsk, tsk!), and he chalked it all up to Microsoft. That by giving so many employees a sizable equity stake, they not only had a vested interest in Microsoft’s success, but also provided this next generation of entrepreneurs with a capital base and the all-important playbook which has become the blueprint for start-up success. Sort of like an inverted pyramid scheme, but one where risk-taking truly reaps its own set of rewards. Of course, maybe it’s just the rain.