There's a fine line between minimalism and unfurnished. I'm trying to find where that line is. [This is a heavily revised version of an old post.]
Simplicity and minimalism tend to go together, but they are not the same thing.
A simple model is one that is easy to understand. Which is a good enough reason for building a simple model.
A minimalist model is one that deliberately gets rid of everything that is not absolutely essential. The whole point of building a minimalist model is not just to make it easy to understand, but to try to figure out what is and what is not absolutely essential to understanding the phenomenon in question. If you have a successful minimalist model, you should be able to add in the stuff it leaves out and add more details to the story without changing the underlying plot. Everything else is embroidery.
Here is some of the stuff my minimalist model of recessions leaves out:
It is a general equilibrium model, but not a dynamic stochastic general equilibrium model. It leaves out time and uncertainty. It's a one-period model, with certainty.
Because it is a one period model, it leaves out saving and investment, borrowing and lending, and interest rates.
It leaves out production and employment. It is a pure endowment economy. Depending on precisely how you define "GDP", GDP is either fixed exogenously, or else zero.
So if you think time and uncertainty, saving investment and interest rates, fluctuations in output and employment, are essential to understanding recessions, my model says you are wrong. My model says those are optional details, that you can add in if you wish, that do not change the underlying plot of the story. They are just embroidery.