again, we have the wrongness of the philips curve screwing everything up again...
inflation is not something that follows a mathematical formula. if there's anything we've learned, it's that we can't create inflation, and we've tried our best to do it, over and over. nothing works..
inflation happens when sellers realize they can charge a higher price because buyers are willing to pay it. that isn't going to necessarily even be a function of costs, either, as prices will come down if the product stops moving due to increases resulting from costs. it's a complicated game of chicken that buyers and sellers play with each other, not some output of a function that can be graphed or predicted.
the counter-example is when you're specifically dealing with rentiers, who will always extract the maximum amount that they possibly can. so, you can be pretty sure that if you give poor people money, it'll just get extracted in rent. but, just about everything else is up to chance, and you want to be modelling it like quantum rather than newtonian physics.
you don't want to say "if this condition holds, inflation happens". rather, you want to say something like "the probability of inflation rests on these conditions". and, you want to build probability distributions to understand it, rather than linear models.
even keen's models were pretty much classical, unfortunately. and, this insight might be unsatisfying, but it's necessary - and you kids should clue into it now. this world isn't causal; you have to understand it using the mathematics of chance, not the mathematics of certainty.
that said, wray's conclusions will still largely stand, if you produce a proper probabilistic model of inflation - in fact, they'll stand way better than any causal model will because it will pull the rug out from under them. the right interpretation is that inflation from producing money is neither certain nor impossible but unlikely - but, it means you always have to understand that there's some chance that the whole thing caves in, that sellers win a series of games and send everything tumbling via some out of control asymptote, and then you're in the weimar republic.
fwiw, there's a good argument that the weimar republic happened because the bankers in england and france wanted it to happen, and not due to some positivist rule of economics - that germany lost that game of chicken, and that maybe they never really had much of a chance of winning it.
and, of course, the reason that the larry summers' of the world are holding off on bigger stimulus is that they don't want it to work too well - you gotta keep the peasants in check, after all. can't have any of that nasty redistribution, of course. so, you produce enough to get the banks in order, and everybody else can starve - which is how they want it to be.
this isn't a theoretical debate - it's a debate about the desirability of the outcome of producing sufficient stimulus.