It is said that a man standing on the edge of cliff does not reason. Today’s global economy is full of cliffs, one of the steepest being the Silicon Valley tech sector, and the men peering over it can be heard chattering nervously about . . . an impending stampede of unicorns. Those uninitiated in the Orwellian parlance of Silicon Valley and its venture capitalist circles could easily mistake such talk for the absurd ravings of a lunatic. But this term has come to describe the primary danger threatening to devastate the tech sector in a cataclysmic repetition of the 1999 dot-com bubble.