Information Cascades and Large-Scale Power Outages
An information cascade is a phenomenon that occurs when an individual makes a decision based on the choices made by previous individuals, instead of acting solely on their own personal information. From Chapter 16, we know that cascades can have significant consequences as a result of relatively little information, and as a result can be very fragile and dependent on the actions of just a few individuals in a network. While information cascades can be widely observed in the various interactions within a social network, the concept extends far beyond these situations and applies to many more network processes, such as that of a failure in the power grid. In a recent study conducted by scientists at Northwestern University, it was found that small vulnerable sets determine large-scale failure cascades in power grids. The study noted that while some power failures can be very local, a nearly identical initial failure occurring under an alternate environment can cause a wide-spread failure in the power grid.
To investigate the reason behind this discrepancy, the researchers conducted a topological analysis of an electrical-circuit network representation of the U.S.-South Canada power grid and found that transmission lines vulnerable to overload failures tended to occupy the network’s core, which is characterized by links between highly connected nodes. From this, the researchers concluded that the association between large-scale cascades and the initial failure was dependent on the triggering failure’s proximity to this vulnerable set. Ultimately, the processes observed in this study represent a very important manifestation of cascades in our daily lives. More specifically, by studying the nature of information cascades and the various factors that contribute to their formation, it is possible to mitigate the occurrences of large-scale failures in the power grid.
Link: http://science.sciencemag.org/content/358/6365/eaan3184