For the United States to get the fiscal stimulus to work, much of their debt will have to be held externally not internally. But this exacerbates the problem of global imbalances. Do you think in the medium term, China and other countries with massive holdings of US assets should be looking to diversify and if so what into?

It's inevitable that in time these central banks will be seeking to diversify: to the degree that the estimated correlations imply that they would be reducing their risks