In the preface of "Increasing Returns and Path Dependence in the Economy," W. Brian Arthur reflects on the evolution of his research and the broader changes in economic theory. Initially, increasing returns were met with skepticism by many economists, who believed they could lead to inefficiencies and government intervention. However, Arthur argues that these ideas have become increasingly accepted and fashionable in recent decades. He highlights the importance of nonconvexities and positive feedback mechanisms in various economic fields, such as international trade, technology, and regional economics. Arthur's journey into this field began in the late 1970s, when he realized that many economic problems involved cumulative or self-reinforcing competition. He developed a framework that could handle increasing returns, drawing parallels with concepts in physics, such as multiple metastable states and phase locking. His work on increasing returns and path dependence gained traction through collaborations with economic historians like Paul David, who popularized the concept through his research on the QWERTY keyboard. Despite initial challenges in publishing his work, Arthur's ideas eventually gained acceptance, particularly after a Guggenheim Fellowship and a meeting in Santa Fe in 1987, where he was introduced to the work of physicists on adaptation and learning. This led to further developments in his research, including connections between learning problems and increasing returns. Today, increasing returns are a vibrant area of research, with contributions from leading economists like Paul Romer, Paul Krugman, and Andrei Shleifer. Arthur concludes by emphasizing the naturalness of transformation, change, and messiness in the economic world, advocating for a more dynamic and probabilistic approach to economic theory.In the preface of "Increasing Returns and Path Dependence in the Economy," W. Brian Arthur reflects on the evolution of his research and the broader changes in economic theory. Initially, increasing returns were met with skepticism by many economists, who believed they could lead to inefficiencies and government intervention. However, Arthur argues that these ideas have become increasingly accepted and fashionable in recent decades. He highlights the importance of nonconvexities and positive feedback mechanisms in various economic fields, such as international trade, technology, and regional economics. Arthur's journey into this field began in the late 1970s, when he realized that many economic problems involved cumulative or self-reinforcing competition. He developed a framework that could handle increasing returns, drawing parallels with concepts in physics, such as multiple metastable states and phase locking. His work on increasing returns and path dependence gained traction through collaborations with economic historians like Paul David, who popularized the concept through his research on the QWERTY keyboard. Despite initial challenges in publishing his work, Arthur's ideas eventually gained acceptance, particularly after a Guggenheim Fellowship and a meeting in Santa Fe in 1987, where he was introduced to the work of physicists on adaptation and learning. This led to further developments in his research, including connections between learning problems and increasing returns. Today, increasing returns are a vibrant area of research, with contributions from leading economists like Paul Romer, Paul Krugman, and Andrei Shleifer. Arthur concludes by emphasizing the naturalness of transformation, change, and messiness in the economic world, advocating for a more dynamic and probabilistic approach to economic theory.