Rosser, John Barkley, 1948-

John Barkley Rosser Jr. (April 12, 1948 - January 10, 2023) was a mathematical economist and Professor of Economics at James Madison University in Harrisonburg, Virginia since 1988. He was known for work in nonlinear economic dynamics, including applications in economics of catastrophe theory, chaos theory, and complexity theory (complex dynamics, complexity economics). With Marina V. Rosser he invented the concept of the "new traditional economy". He introduced into economic discourse the concepts of chaotic bubbles, chaotic hysteresis (op. cit., p. 326), and econochemistry. He also invented the concepts of the megacorpstate and hypercyclic morphogenesis. He was the first to provide a mathematical model of the period of financial distress in a speculative bubble. With Marina V. Rosser and Ehsan Ahmed, he was the first to argue for a two-way positive link between income inequality (economic inequality) and the size of an underground economy in a nation. Rosser's equation has been used to forecast ratios of future Social Security benefits to current ones in real terms.