Summary: As the migrant crisis in Europe worsens serious steps to address it are being considered.

One proposal is for passports to be required in order to cross from one EU country to another.

Would such a drastic move spell the beginning of the end for the Eurozone as a viable entity?

And if so what will happen to the piles of sovereign debt that's been issued by the economically vulnerable EU PIIGS, and to the investors who have been pouring money into them at what appear to be ridiculously low yields?

A funny thing happened on the way to global investors reach for return and, one would assume, desire for preservation of capital!

I speak of EU sovereign debt and the severe contraction in the level of yield demanded by investors for the bonds of what had at one time (and actually still are) been affectionately referred to as the EU PIIGS.

The acronym PIIGS stands for those countries, Portugal, Ireland, Italy, Greece and Spain, who once upon a time had been considered candidates for potential debt default (depending of course on what your definition of a bond default is).

Comparison Over Time Of Select Sovereign EU And u.s. 10-Year Bond Yields

Country                May 2012            April 2014          February 2016

United States           1.77%                        2.69%                         1.67%

Germany                    1.47                           1.47                            0.26

Portugal (P)              11.0%                       3.91%                          3.73%