It was there when I first studied economics. A feeling that I understood microeconomics, but not macroeconomics. Getting old, I think I know why. Micro is built on clearly articulated foundations, but macro had to go through a period around the 1970s when it had to be given its “micro foundations.” Robert Barro and Herschel Grossman even wrote a textbook from that ongoing work, and I was in a class of Brown University graduate students who went through their book in draft form.
But lately it seems that both pieces of micro and macro are groping for “institutional” foundations. An example is Willem Buiter’s recent piece on the state of macro.
For more, see my lecture on the difference between micro and macro.
Frank and Ernest have their own take on the phenomenon of disagreeing economists: