Many organizational populations display increasing variation over time in characteristics thought to be central to survival, as we show here for hard disk drive producers. We develop a simple model that might account for this pattern. In it, technological advance follows a trajectory consistent with a proportionate random process (akin to a Gibrat process) that favors technology leaders but only stochastically. We demonstrate through computer simulations that evolution in an organizational population with selection favoring a characteristic evolving as a proportionate random process can, under plausible conditions, generate increased variation over time.
