An interesting post by Brad DeLong here. The first item in it that is too little noted is that JB Say changed his mind about general gluts:
'Yet Say changed his mind. By 1829, in his analysis of the British financial panic and recession of 1825-6, Jean-Baptiste Say was writing that there could indeed be such a thing as a general glut of commodities after all: "every type of merchandise had sunk below its costs of production, a multitude of workers were without work. Many bankruptcies were declared..."'
That's correct. In the Malthus-Say debate, Say conceded to Malthus. Which makes a comment like this one interesting:
"Say emerged victoriously from his polemics with Malthus and Sismondi."
Well, except in his own eyes!
Secondly, DeLong clarifies something that only became apparent to me last year: the deepest divide in macro is between those who believe that general overproduction is possible and those who think that only sectoral imbalances can occur. The list of adherents to the latter view is interesting here: "Think of Karl Marx, Friedrich Hayek, Ludwig von Mises, Andrew Mellon, Robert Lucas, et cetera."
That's right: Marx.