Great inventions lead to unexpected consequences. Consider how the invention of electricity triggered rapid innovation and transformation in telecommunications-first came the telegraph and the telephone, then radio, television, and finally, digital convergence over the Internet. These innovations transformed war, politics, education, shopping, and countless other aspects of modern life. But it is often the social, economic, and even cultural effects of electricity that truly help inventions go far beyond what could have been expected by their inventors. The music industry exploded with the gramophone, health was transformed with radiology and imaging, the airline industry owes its existence to cheaper aluminum, while urban landscapes were transformed by elevators and subways. Each of these examples shows the importance of electricity as a "general purpose technology"-a technology "that can lead to the creation of many sub-inventions" (Gordon, 2017). And that is precisely what blockchain is: a general purpose technology.