I'm with ArmoTrader - there's a lot of fuzzy thinking going on in the main article and replies:

* " For starters, the underlying unit is currency (e.g. yen, dollars, etc.) which itself changes." How does the currency itself change? What do you mean?

* "Second, government spending often has a negative multiplier (meaning that 1$ in deficit spending leads to less than 1$ of GDP growth). It’s growth, just unproductive growth. Third, there is a fundamental relationship between private sector spending and government spending. The only question is one of capital allocation. Would each dollar be better spent by the government or by the private sector?"
I was under the impression that government spending in Japan was keeping up aggregate demand, because the private sector was winding down their balance sheets (see Koo's idea of a balance sheet recession). In which case there is no concept of crowding out that Rimkus is implying.

* "Surplus countries like Japan have used their CB to lower rates, stimulate debt and regulate banks into buying more JGB’s."
A bank buying a JGB is more like an interest rate swap than a purchase. Rather than leave money in the BoJ earning a floating rate of interest, a bank accepts a fixed rate of interest for a known length of time. In both cases the government is the counterparty - either the Treasury or the BoJ. If in the future nobody wants to do the swap (buy the bond) then the cash just sits on the BoJ balance sheet and gets 0% interest.

Japan has problems, but the analysis is deeper than this.