refers to a school of heterodox macroeconomics thought in the US in the early 1970s; centered around coastal universities (Ivies, Berkeley, etc) whereas freshwater economics referred to schools around the Great Lakes; primarily a methodological disagreement about the extent to employ the theory of economic decision making; the divide no longer really holds true today
Eichengreen belongs to the last generation of so-called ‘saltwater’ macroeconomists trained by Yale, MIT and Harvard in the 1970s and early 80s.