The mysteries of growth and change

Who started trending first among these lines?

Here we have government savings, the negative of deficit, in red. See it climb from late 2012. Then we have the trade savings, in blue, see it trend up starting in early 2012. See the dollar trade weight value,in green, trend up starting in mid 2011.  I scaled the dollar values to fit and the units are relative.
Growth in the dollar economy was discovered. Also the spending deficit suddenly started reductions, after the events, as if tax hikes were necessary to accommodate growth. What is that mysterious growth spurt we see pop up now and then? The endogenous adaptation to reduced trade? Or just a US bounce back from disappointment in emerging market? Early signs of austerity's success? Expectations of higher taxes?  Britain also experienced a mysterious growth spurt and deficit reduction. Did Britain follow or lead? The evolved squirrel may have unknown powers of 'figuring it out', and we underestimate the little fellows.
There is a new study from Europe, HT Thoma, that shows tax hikes more effective for austerity expansion than government cuts. That shows government spending has a slightly higher than one value, using my units, in Europe now. But tax hikes had the multiplier of 2.0, an austerity win.:

The commission paper goes into further detail, assessing the impact of austerity through spending cuts versus austerity through higher government revenue. In the case of Spain, for example, the new draft research shows that for every euro in spending cuts, 1.1 euros were lost in the economy. The impact of reducing the government’s deficit through raising more revenue would have taken 0.5 euros out of the economy for every euro in revenue.

I could believe that, but the ability of European governments to fine tune things to within 10% is unlikely, it is still a sparse solution set over there.

Is austerity the mysterious driver? My theory of relative government inefficiency in the USA still stands.  But a bunch of other theories will have to drop out of the race, in the USA. The IMF theory that multipliers suddenly get better at zero bound was a biased sample, they simply measured the multiplier needed to survive. The various legislatures are getting the needed multipliers by acknowledging the expansive power of austerity.