Yep, but I don't think he does. He specifically says
And this is what the study in part shows. The focus on a declining profit rate in the United States also shows a correlation with a decline in 'productive' investment in that area which in turn leads to weaker growth in outputs and incomes, higher unemployment, and rising debt burdens, more problems for Capital in the United States in particular. It explains the particular circumstances of the United States, it doesn't imply that these same problems are happening everywhere in the world at this point in time. It's just demonstrating an empirical tendency/movement that happened in the most 'advanced' capitalist country in the world. And that it's not beyond the grounds of belief to suggest that if we see this development (and correctly explain the reason for that development) in one advanced capitalist country, then ultimately we can make some kind of assumptions/guesses that eventually the same thing will happen elsewhere (with the outcomes possibly far worse as the opportunities to find new 'outsides' get less and less as capitalism becomes more established and more embedded in all walks of life and in all geographical areas)
I don't think he means that consumer demand doesn't really matter - he just says it's not the only thing that matters and that if productive investment rises as consumer demand reduces (bear with me!) then this means that a decline in wages or worker's share of income doesn't always lead to a decline in total demand, and therefore cannot be the cause of economic crisis or recession.
I agree that it does sound somewhat counter-intuitive - but production under capitalism in general sounds a bit mental to me. I mean to take it back a stage, there's a huge amount of production of consumer goods that no one really needs or even can afford, there's a huge amount of wastage that goes on for a huge amount of time. I think we all agree that this happens in relation to the production of means of consumption, so all Kliman is saying that the same thing also happens to the production of the means of production. There's a large element of 'production for production's sake' going on there. The underconsumptionist argument seems to rest on the claim that all production is always ultimately production for human consumption.Now in a progressively planned economy or in an economy where real need was the driver, all production would be ultimately production for human consumption, but we know that in capitalism things don't work like this, so while Kliman's argument may seem counter-intuitive initially, it has to be placed in the context of the overall counter-intuitive and warped set of production relations & motivations that is capitalism.
Also as labour productivity increases the composition of capital in general increases and increases, this means that more and more of individual capitals is made up of non direct labour inputs (i.e. more C and less V in marxist terms). This means that more and more productive investment/demand is required for each circuit of capital with the proportion of direct labour in there ever reducing (leading to the tendency for the rate of profit to fall etc..). So the empirical data that shows a gap opening up between 'productive' investment demand and consumer consumption demand, is pretty much showing the dynamics Marx talked about in terms of increased labour productivity leading to an ever increasing compensation of capital resulting in decreasing profit rates (not decreasing absolute levels of profit, but decreasing profit rates given the huge relative amount of constant capital relative to variable capital).
So this shows again the relative importance of the production of means of production, and the demand for/of productive investment over and above ultimate consumer demand. This doesn't mean that this is a stable situation, but this is the whole point, capitalism is not a stable set of production relations.
There's also more logical explanations for it in terms of timings of things, which means that the argument that the underconsumptionists put out which says if workers share of income or real wages is decreasing then overall demand will fall and this will cause crisis. But in times of reduction in demand from labour, capital can still have its eye on ten years, twenty years ahead (airports, roads, infrastructure etc.) for when consumer consumption may rebound (artificially through debt or otherwise). Although this isn't really part of Kliman's structural argument.
The other thing is, this book is an empirical study. He's not putting forward a detached theory as to what he thinks goes on, he's crunched the numbers and draws his theory from that (so much so that he now disagrees with a lot of what he said in 2009 prior to doing this study). For example his number crunching reveals that prior to 2009 when everything dropped, for the previous 75 years prior to that - productive investment grew 73 fold while GDP only grew 18 fold and personal consumption 15 fold. So productive investment grew four times as much as GDP and five times as much as personal consumption.
Now some of that productive investment could be driven by investment which US capital hopes to or does derive overseas consumer demand from so that is where the single territry study starts to loose some of its explanatory power as this would mean this gap between investment demand and consumer demand is overstated (however at the same time the consumer demand shown is likely to include a huge amount of demand for commodities produced by overseas productive investment, which would actually mean the gap shown on the graph is understated, and should be even bigger), however the sheer size of the gulf there between productive demand and consumer demand (in a time when debt was also being used to fuel consumer demand) does say something
Now Kliman is not saying that this is a stable situation which can go on for ever, as capitalism cannot be said to be such a thing - but these kind of figures do show that the underconsumptionist claim that crisis is caused by a lack of consumer demand, don't have that much explanatory power.
I do think there is a large amount of sense in what he says both from a logical and empirical point of view - and if it at first appears counter-intuitive it shouldn't be written off straight away. I mean there once was a time when political economy took it as read that increased labour productivity would lead to an increase in the rate of profit rather than a decrease, and that a decrease in profit rates in the face of increasing productivity seemed like something totally counter-intuitive. Anyone who is familiar with Marx's work would not see that as something counter-intuitive, but at first glance it can appear to be