Cuttings from mine of 5 Feb:
No debt produces anything. New uses of credit can sometimes be for productive purposes. But after that money's spent, nothing remains but the evidence that it was credit we were spending: Nothing remains but the debt. And the cost of debt over time is equal to the economic boost we get from credit use. Equal, or greater.
Borrow a dollar today, spend it today, and boost the economy today. Tomorrow, all that remains is a dollar of debt, the cost of interest on it, and the cost of repayment. These costs do not boost the economy. Just the opposite. This is true, no matter who borrowed the money. It is true, no matter what the money was used for.
To boost the economy, a new use of credit must be large enough to completely offset the drag created by existing debt, and then some. But the use of credit makes existing debt bigger. See the problem?