> what they forget (or more likely, choose to ignore) is that investments can be just bad investments Do you have evidence that someone forgot or ignored this

> what they forget (or more likely, choose to ignore) is that investments can be just bad investments Do you have evidence that someone forgot or ignored this issue? Quotes from a particular central banker, for example? I don't think this part informs the conversation. The question you raise, while maybe novel to some of us on HN, has been long discussed and examined in economics. There are indicators of over-investment and under-investment, and trade-offs to different central bank financial tools. Finally, because a central bank tool increases investment, that doesn't mean the level of investment becomes too high; it could have been too low before. It's like watering a plant; it might help or depending on its prior condition the same action might over-water or under-water it. One sign there is under-investment, as I understand it, is that extremely low/negative interest rates are not stimulating inflation. This suggests plenty of under-utilized capacity.