Money under the mattress does affect the economy, by changing its owner's willingness to part with a marginal dollar. If I have $1k under the mattress I probab

Money under the mattress does affect the economy, by changing its owner's willingness to part with a marginal dollar. If I have $1k under the mattress I probably won't risk $100 on a share of CORP. If I have $100k under a mattress, I'm more willing to take a swing.