I don't think the problem is the money supply per se. Companies typically need to borrow money in order to finance new production and create jobs. If credit becomes tight, and companies can't borrow, or if borrowing becomes too expensive, then people start losing their jobs., production sags, etc.
But then you have something new to question. What cause credit to be tight? Where it all starts is not clear, although I'm pretty sure there are some here who think they have the answers. Just get ready to sift through the political rhetoric.
Anyways my little adhoc analysis is somewhat simplistic, but it's not too far from the truth.
A very key part of the picture, and one that is perhaps difficult to predict or control, is how people feel about the economy, how confident they are about the future, etc.
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