In these cases, and as has long been acknowledged (for example, with reference to the sharp rise in house prices in the United Kingdom recorded in the early 2000s), it is obvious that it is necessary to resort not so much to monetary policy but to prudential instruments, with limits on the value of collateral that can be used in taking out a loan.
As we have learned, the impairment of a few factories in just one country can have a significant impact on policy choices in other countries, as we see here in Germany, on an entire industry worldwide and, ultimately, on the global economy.