Still, I'm hesitant to draw the conclusion that giving cash to someone with a high MPC results in a markedly higher amount of consumption/expenditure in the economy, as if alternatively that cash was invested by someone with a high MPS it would be eventually spent anyway. Of course there would be some frictional element to this (money needs to be transferred when invested, etc) but I posit that more is made of this than should be.
It'll end up in the deficit just like everything else. As it should. Unlike QE{I,II,III}, this will increase the base.
Saving and spending are both morally neutral; it's just that we think it's Good To Be A Rentier, so we (curiously) bias in a moral case for saving. The New Testament of finance :) allows for bankruptcy, to implement a mechanism for forgiveness.
Saving is pragmatically good. But we seem to make a moral fetish of it - in fact, if our neighbor spends, spends, spends, we benefit. But Liberal Atomism doth make hypocrites of us all...
Ignoring all this, monetary velocity is important and all other things being equal, I'd rather have it than not have it.
Otherwise...
While there is an element of truth to that, see "the marginal value of a dollar". You "spend" your ten millionth dollar quite differently than you spend your ten thousandth.
Some of these guys for whom money is simply a means of keeping score won't change their consumption patterns much no matter what.
If you want to increase velocity, the way to do it is cause more cash to be in the hands of broke people.