Wednesday, May 20, 2015

Graphical version of my view of mathiness

Here is this post represented in graphical form ...

1. I like these diagrams. It would be interesting to see how different economists would draw this type of diagram.

If I were drawing an equivalent, I would use multiple arrows with each representing one facet (or perspective) of economics. For example:

Arrow 1: study of universal natural laws – Newton and Einstein belong here (physics, chemistry)
Arrow 2: study of complex natural evolving systems – Darwin belongs here (biology, geology, psychology)
Arrow 3: study of complex man-made evolving systems (everything from washing machines to traffic flow to economic institutions)
Arrow 4: study of politics and history.

I think that the mathiness problem arises because economists think of themselves as living on arrow 1, so they are trying to be the economic equivalent of Einstein and Newton. However, as far as I can see, that only works for simple systems with a small number of parameters or for systems where most phenomena are assumed to be random (as per your work).

I think that economists should live on all four arrows and should share insights across the arrows. I suspect that different types of maths are required on different arrows with the least maths on the politics and history arrow which I think is probably the dominant arrow in macro.

If I’ve understood your arrow correctly, you see Paul Krugman as being more advanced than his contemporaries. I agree but I think that is because he is better at communicating economic ideas to the public. Also, he applies rules of thumb (different rules in different situations) rather than fundamental rules in his analyses. It’s not because he uses more maths. This is much more in tune with my experience of working at the micro level in many public and private organisations. Why do you think Krugman is more advanced than his contemporaries?

Also, out of interest, why do you see Newton being more advanced than Einstein and Darwin when he came before them? In your mind, what is the thing at the end of the arrow that Newton has more of than the others?

1. The relative locations of Newton et al were not meant to be definitive -- I did put Newton at the front because he basically invented the discipline of physics, whereas Einstein and Darwin came up with organizing principles of existing disciplines, albeit extremely important ones. Darwin's was more critical in biology than Einstein's was in physics.

Krugman was left at the high end partially as a joke on a common trope in the econoblogosphere ... but also because of this.

Overall, that is an interesting classification. I'd definitely see how 2 and 4 are separated and how economics seems to fall in between with a lot of its issues stemming from the tension between 2 (things that exist without humans) and 4 (things that exist only because of humans).