There are many arguments for the use of models in economics, including notions of rigor and transparency, or that models can help you to see relationships you otherwise might not have expected. I don’t wish to gainsay those, but I thought of another argument yesterday. Models are a way of indexing your thoughts. A model can tell you which are the core features of your argument and force you to give them names. You then can use those names to find what others have written about your topic and your mechanisms. In essence, you are expanding the division of labor in science more effectively by using models.
This mechanism of course requires that models are a more efficient means of indexing thoughts than pure words or propositions alone. In this view, it is often topic names or book indexes or card catalogs that models are competing with, not verbal economics per se.
The existence of Google therefore may have lowered the relative return to models. First, Google searches by words best of all. Second and relatedly, if you have written only words Google will help you find the related work you need, scholar.google.com kicks in too. In essence, there is a new and very powerful way of finding related ideas, and you need not rely on the communities that get built around particular models (though those communities largely will continue).
It is notable that open access, on-line economics writing doesn’t use models very much and is mostly content to rely on words and propositions. There are several reasons for this, but this productivity shock to differing methods of indexing may be one factor.
Still, it is not always easy to search by words. Many phrases — consider say “free will” — do not through search engines discriminate very well on the basis of IQ or rigor.