You missed investment, which would be four possibilities of increased labor productivity, not three.  It is entirely possible that investment can increase in addition to or even in lieu of consumption.  

You also missed a fourth possibility on how consumption (or investment) can be increased:  D) Plunder. Through use of power, strong groups can simply take resources from other, weaker groups.  This means that it is entirely possible and even sustainable for a strong enough group of political elites (such as, say, the financial-governmental-academic-military class of the United States) to redistribute wealth from other laborers and capitalists throughout the world when needed to prevent a collapse of the social system.  

I was wrong when I said "no relationship has yet been hypothesized" between labor productivity and the current economic crisis.  There is, of course, a very solid hypothesis, called Marxism, for that.  What I meant was that a decline of labor productivity has not been advanced as a cause of this crisis.  Your argument, however, is the opposite, and it's the Marxist one.  Most schools of Marxism also predict that redistribution of resources from some capitalist countries to others (e.g. WWII) allows a recreation of the relationship between capital and labor that can conceiveably provide for an eternal capitalist system. (Something which Marx himself hadn't considered.)  Plunder by some capitalists of the wealth of others allows capitalism to continue by recreating the conditions of surplus profit in plundered areas.

What are some examples of plunder in a modern economy?  War, of course, is one -- the devaluation of capital through physical destruction of capital and labor.  Another one, however, is when a lender must transfer wealth to borrower who defaults or otherwise changes in payment arrangements (e.g. inflation). The borrowers, on net, have gained in the current crisis by not repaying banks, and strong, national borrowers such as the US, gain at the expense of foreign lenders such as the Chinese, by both not repaying investments in things like mortgage-backed securities and by paying effectively negative real interest on the only available means of insuring wealth -- government securities. Both involve massive transfers of resources from back weaker capitalist states to stronger ones.

Plunder, in this way, is not prohibited by western ideology. (I'd argue, rather, that it is central to it.)