It's from the Collected Works. I archived it so I could contrast Keynes' theory from Douglas'. It is more accurate to say that the incomes of the public plus the increased valuation of the capital owned by the public equals the costs of production. Keynes also inaccurately defines business profitability. Actually, businessmen in general, in an expanding economy, are always receiving less from sale proceeds, measured instantaneously, than they are spending.
Profit derives from accrual accounting, which delays the expensing of costs into the future.
Bill, Some weeks ago, Mark Adkins posted to sci.econ an idea about the need for a money input to make the system work. I was puzzled by it and never got it straight in my mind. This is such an explicit exposition that I'd like to see it posted or at least well-publicized on sci.econ. I was tempted to post it there but thought it better to ask you about it. I wonder now about the rest of that lecture series.