The above chart shows that the USA economy performed marginally better than the Euro Zone during the first three quarters of 2015 (2.1% GDP growth as against 1.6%)
However, the Euro fell a total of 25% against the US dollar between Apr 2014 and Dec 2015.
Euro Zone policy favours continuation of low interest rates and Quantitative Easing, while USA contemplates raising interest rates and paying off QE debt in 2016. These differences in policy do not justify the continuance of the low value of the Euro.
I believe the EUR/USD is at or around the bottom of its down-slide and will commence an upward trend soon.
I show my prediction for the Euro in the following chart: EUR/USD to reach $1.2 by next July and $1.25 by end of 2016.