This is not a German miracle, its simple demographics, most of the Germans are in their productive years of 40s and 50s and their population in teens and 20s is tiny, so their investments are low even though at per-capita level they look tremendous. This is the reason why Germany's hope is automation. They are demographically not in a great place. of course, this will come home to roost in 20 years or so.
[edit] Demographics link: http://www.indexmundi.com/germany/age_structure.html