This excerpt originally appeared in IEEE Spectrum on August 14, 2012.

Tyler Cowen, an economist at George Mason University, has posed a fascinating question on his blog: “What is the most underrated innovation of the last 100 years?” Cowen suggests four candidates: Alan Turing’s insights into computation; the chemical fixation of nitrogen from the air for use in fertilizer; what he loosely calls “various developments in electrical engineering, including better transformers;” and more recently, Amazon’s warehousing and shipping practices, which Cowen thinks will mean the “death of much of retail.”