The cryptocurrency Bitcoin has become a center of excitement, mystery, and controversy. Boosters have viewed it as an investment opportunity, a financial innovation, and a rival to state-controlled currencies; skeptics think it is an energy-wasting market bubble. MIT economist Robert Townsend sees things differently. To Townsend, Bitcoin, for all its novelty, is part of a larger family of financial innovations, known as “distributed ledgers,” which allow people to perform financial activities without requiring a central authority to keep a master copy of those transactions and while minimizing the need for…
