The differences between the economic science "schools" are not that stark. Instead, the difference is often merely about the value of some key variables - and that uncertainty is the result of difficult observation of said variables in limited datasets.

It's like geologists agreeing on tectonics, but not being sure about the drift speed or even drift direction.


The key difference between Keynesians and others is for example almost entirely about the value of a single multiplication variable'; is it larger than one or not? Studies yielded conflicting results.
http://en.wikipedia.org/wiki/Spendin...timated_values

The different economic schools are not so much incompatible in their formulas as in their assumptions.