Also in the HES/AEA session I organized in Atlanta was a paper by David Colander and Casey Rothschild entitled, "Sins of the Sons of Samuelson: Vision, Economic Pedagogy, and the Zigzag Wadnerings of Complex Dynamics," available at this link. They argue that Samuelson was aware of complex dynamics and how math models could simplify insights in Marshall and others that had been expressed only in the "zigzag wanderings" of literary expression. They blame the "sons of Samuelson" for turning the push to math models, certainly led by Samuelson, into a mindless dogma that oversimplified economics and misled many in many different ways. They proposed how to change intro textbooks to open students' minds to complexity (and Rothschild will be joining Colander as a coauthor in future editions of his popular intro textbook).
Rajiv Sethi has just posted on Samuelson's own interest in nonlinear dynamics, citing my mentioning a paper by Samuelson on Mark Thoma's blog, with Thoma linking to the Sethi piece. Sethi discusses the nonlinear version of Samuelson's multiplier-accelerator model, which appeared in the same year (1939) as his much more famous linear version. Sethi notes that I had brought this up on Thoma's blog only two weeks prior to Samuelson's death.
As a matter of fact I cite that paper by Samuelson in the paper I presented in the session at Atlanta, "Chaos Theory Before Lorenz," available on my website and also having appeared recently in print in a special issue of Nonlinear Dynamics, Psychology, and Life Sciences, honoring the late Edward Lorenz, the MIT climatologist who was reputed to have "discovered chaos on a coffee break" back in 1961. He was the person who coined the term "buttefly effect."