Searching for the microfoundations of macroeconomics

I concentrate on the discussion of the reasons why, in the 1970s and 1980s, the so-called New Classical Macroeconomics became the dominant paradigm, despite the progress made in the search for microeco- nomic foundations more satisfactory than the New Classical assumptions of perfectly competitive markets that always clear. The second issue that I briefly consider concerns the hypothesis of imperfect competition and its im- portance for disequilibrium macroeconomics as well as other approaches.