Robert Vienneau — Nell's Diagram Of A Capitalist Economy by Robert Vienneau

I like the clarity with which monetary flows and commodity flows are distinguished in this approach. It is not the case that capitalists own blast furnaces sitting in their backyard, which they then loan to firms. Mainstream economists are deliberately and consistently obfuscating on this issue, from introductory teaching to beyond. Perhaps there's a reason for this widespread confusion:

"From the point of view of Political Economy, however, the most important fact is that while wages are paid for work, and one can (and in some circumstances should) think of the wage bill, equal here to Worker Consumption, as reproducing the power to work, profits are not paid for anything at all. The flow of profit income is not an exchange in any sense. The Samuelson [circular flow] diagram...is fundamentally misleading; there is no 'flow' from 'household supply' to the factor market for capital. The only flow is the flow of profit income in the other direction. And this, of course, leads straight to that hoary but substantial claim that the payment of wages is not an exchange either, or at any rate, not a fair one. For Wages plus Profits adds up to the Net Income Product; yet profits are not paid for anything, while wages are paid for work. Hence the work of labor (using the tools, equipment, etc., replacement and depreciation of which is already counted in) has produced the entire product. Is labor not therefore exploited? Does it not deserve the whole product?" -- Edward Nell

Read the whole post at Thought Offerings (short)
Nell's Diagram Of A Capitalist Economy
by Robert Vienneau