I’m very skeptical. It is of a brand of macro that I think of as one-identity-economics. You take an accounting identity. You assume that certain terms of it are fixed. And you then derive conclusions–in this case, that the growth of the budget deficit has moderated the fall in private savings.
The problem with one-identity-economics lies with the assumption that certain terms in it are fixed. There are lots of channels of adjustment in the world economy, and it is a safe bet that with different levels of interest rates and different levels of wealth we would see different levels of corporate investment and of net exports.
Some other examples of one-identity-economics are the crowding out hypothesis and the twin deficits hypothesis.