“[I]t’s very inadequate. I think there are situations in which parts of the theory can give you a little bit of insight. It’s not that I am against the theory, per se, as against the hegemony of the theory. I actually think supply and demand analysis can be a useful sort of heuristic device for some things. Where you get into problems is where you start to believe there are actually supply and demand curves out there in the real world and firms actually draw marginal cost curves to come to their decisions. Then you’re starting to take that a lot too seriously. In the curriculum materials I worked on – people are kind of under obligation to teach certain sorts of things in introductory courses, but I think it makes a big difference whether you treat something as “this is the way the world works” versus “this is the way some people have thought about explaining how the world works”. So, neoclassical theory is one of these tools – I often summarise my views as “broader questions and bigger toolbox”. I think economists should be dealing with things like inequality and climate change, the big questions, and use a bigger toolbox to do that. Neoclassical theory can play a role, can be one of the things in one of the compartments in the toolbox, but it’s clearly inadequate also for a lot of other things like deciding at what rate we should combat climate change. Basing that on a mathematical model and a market interest rate is stupid.”
A. Mearman, S. Berger and D. Guizzo (2019), ‘Julie Nelson’ in What Is Heterodox Economics? Conversations With Leading Economists, Abingdon: Routledge, p.120-121.