I would have included what follows in the previous post, but was afraid of putting too much into one post. So, a bit more.
Here is the precise quote from Summers's talk about the conversation between Ken Arrow and Paul Samuelson on the evening of the celebration in 1972 in Cambridge, MA.
"Almost everybody left and Paul and Kenneth were discussing turnpike theorems. Kenneth was discussing aspects of Pontryagin's maximum principle. Paul was discussing how stupid Joan Robinson was."
So somehow Larry Summers thought that it was appropriate at this ultimate commemoration of Ken Arrow at the Tel Aviv Institute for Advanced Studies to pull out of what was reported to be a very long discussion that had their wives getting quite impatient, and which Larry himself noted was, well, the two Nobel prize winners in the room going on and on as I am sure they did about all sorts of matters, many of them highly mathematical, that Larry decided to quote as the one contribution by his other uncle, Paul Samuelson, this snide remark about Joan Robinson, which looks pretty ridiculous and hypocritical in light of his humiliating admission only six years earlier that this "stupid" Joan Robinson had been right and he had been wrong.
Let me add some not so well known further weird details about all this. The first is that after Paul Samuelson walked down Mass Ave from Harvard to MIT after the anti-Semites at Harvard refused to hire him there, in the first year that he was in charge of admitting potential grad students at MIT he rejected his future quasi-brother-in-law* for admission to the grad program, yes, rejecting Kenneth J. Arrow, right up there in stupid decisions along with approving of that incorrect paper on the surrogate production function by various of his grad students in the QJE that led him to confess about the "foundations of sand" upon which economics is supposedly based. (Among those accepted in that class instead of Arrow was Lawrence Klein, a future Nobel Prize winner and Samuelson's first PhD student.)
Yeah, pretty embarrassing. As it was in the end, Samuelson was more worried about Arrow-Debreu(-McKenzie) general equilibrium theory, which he did not do, than he was about Robinson and the Cambridge capital theory controversies, and so he hired Duncan Foley, who got his PhD from Herbert Scarf at Yale, to come to MIT and help him teach grad micro theory there. Duncan did that, later going to Stanford and falling into heterodox Marxist sin and not getting tenure there. But Samuelson got his new orthodoxy, which was taught to people like Krugman and Akerlof and Varian, and others, establishing neoclassical orthodoxy, although it still lacked game theory.
Regarding Arrow and the Cambridge capital theory debates, to the best of my knowledge, he never said a word about them. He coauthored a famous book on general equilibrium with Frank Hahn in 1971, with Hahn playing a defender of neoclassical theory, although granting much to the Robinson crowd. That Samuelson's defense was to retreat to heterogeneous capital being the true way to go is ultimately profoundly ironic, given that he rejected his future quasi-brother-in-law for entrance to MIT's grad program, the general equilibrium guy whose model was ultimately totally decentralized..
In any case, Summer's tossed-off quote from Samuelson looks really shameless, aside from being historically seriously intellectually misleading. Why did he do this? I do not know, but it is shameful.
*The parents of Lawrence H. Summers both worked at the Philadelphia Fed, with his father also at U. Penn, and the inventor of the concept of PPP international measurements. His mother,Anita, was the sister of Kenneth J. Arrow, and his father the brother of Paul A. Samuelson. His father, Robert changed the name from Sanuelson to Summers in an effort to avoid anti-Semitism when he arrived in the US . Robert kept it, but Paul decided to retrieve the original name, which is why Larry is Summers rather than Samuelson.