W. Brian Arthur is an economist, and one of the early researchers in complexity (the science of how patterns and structures self-organize). In the 1980s and early 90s, he led the Santa Fe Institute's team researching the economy as an evolving, complex system; this work has developed over time into the new thinking called complexity economics. Arthur is also well known forhis pioneering theoretical work on positive feedbacks or increasing returns in the economy. What happens when products that gain market share find it easier to gain further market share and their role in locking markets in to thedomination of one or two players. Arthur has been Morrison Professor of Economics and Population Studies at Stanford, and Citibank Professor at the Santa Fe Institute. He is a Fellow of the Econometric Society; and the recipient of the Schumpeter Prize in Economics in 1990, the Lagrange Prize in Complexity Science in 2008, and two honorary doctorates. His books include Increasing Returns and Path Dependence in the Economy (1994); and The Nature of Technology, What it Is and How it Evolves (2009).