On this podcast. As many commenters point out, Solow has a lot of acuity (and stamina!) for someone aged 90.

I think that in their discussion of what people believe in macro and why, I prefer Solow’s rendition. I think he is correct that it was not as simple as saying that Chicago taught monetarism and MIT taught fiscalism. (Small world note: Roberts’ undergraduate friend who went to MIT was my roommate during our first year of graduate school.) I think Solow is correct that the AS/AD paradigm was very different from what came before. However, I would note that until the 1970s, it was the AD paradigm alone, with the Phillips Curve (popularized by Samuelson and Solow) tacked on. In the 1970s, as economists started to think more about inflation and about what sort of theory might explain the Phillips Curve, there emerged the AS-AD paradigm. Most of the macro that came out of that 1970s theorizing ended up going in a direction that neither Solow nor I liked. As I point out in my macro memoir, that is how I was drawn to Solow as a thesis adviser.