Made in Germany explains the base interest rate. What makes it the linchpin of the financial markets? The base rate affects the affordability of bank loans, the quantity of a given currency in circulation and the pace of economic growth. When it's low, commercial banks get cheap credit from the central banks. They can pass those low prices on to companies and individuals - who, in turn, will tend to invest and purchase more. Lots of money goes into circulations, but too much can trigger inflation. Then the central bank has to raise the base rate and put the brakes on economic growth. That can turn up the pressure on deeply indebted countries.

More from this week's edition of Made in German: http://www.dw.com/en/made-in-germany-the-business-magazine-2015-10-20/e-18754293-9798