Why the expansionary monetary policy is not having any impact on the German economy

Despite the extremely low interest rates, Germany has maintained a huge excess savings over investment, which shows the ineffectiveness of the expansionary monetary policy in Germany. This can be ascribed to: The fear of population ageing, which means that the household savings rate has risen despite the low interest rates; The absolute rejection of a fiscal deficit, which explains why the German government has not taken advantage of the low interest rates to conduct a more expansionary fiscal policy; The expected contraction in "old industry" (automotive, chemicals, industrial capital goods), which explains why companies have not used the low interest rates to invest more. This would normally lead to greater use of fiscal policy in Germany if growth slows down.