The ranking puts German growth prediction to be almost zero while Japan's to be 2.8? I call this rubbish. Both countries were in the last years demographically pretty similar. Both countries are however diverging pretty swiftly. While productivity in Japan was falling it was increasing in Germany. Moreover the recent development showed that Germany was making gains in demographics with higher birth rate and net migra…
First, higher birth rate and net migrations are usually a (short-term) drag on GDP, not a boost.
Secondly, you can't look at Germany outside the context of being a member of the EU and Eurozone (and currently a very important creditor in the Eurozone). That has a huge impact on Germany's economy.