Keynes allowed for mobility in the ownership of capital. But Kalecki, with his emphasis on the financial constraints limiting the scale of enterprise, viewed capital as a social barrier. Sebastiani points out one other difference in these theorists' account of the roots of economic stagnation. Keynes emphasized the importance of expectations, and in effect the fragility of beliefs as the reason for the insufficiency of investment. But for Kalecki, investment is the weak spot of the capitalist economy because of structural factors.
Productive capacity tends to run ahead of absorptive capacity.
And while higher levels of investment spending will, in the short run, close this gap, in the longer run they will widen it. Sebastiani then proceeds, in Part II, to examine Kalecki's work in light of Marx, the Stockholm School, and the Post Keynesians. References Kalecki, Michal. Oxford U., 1991-93. The economics of Michal Kalecki.