In the US, we have low interest rates engineered by the Fed (1.7 percent on the 10-year T-bill, the last I looked). The low yield would seem to suggest that people seeking income would not purchase government bonds -- right? Instead, they would be likely to purchase equities, particularly equities with a decent yield. But if income investors are forsaking government bonds for equities, wouldn't that have the effect of driving up the price of equities, under simple supply-and-demand principles? Add in fund managers who, I think, don't want to be caught with high-priced, low-yield bonds in their portfolios, because a 1.7 percent return doesn't look very good. Again, it would seem they would be inclined to put money into equities, again increasing demand (and price). Wouldn't it follow, then, that ultra-low interest rates are fueling a stock market bubble? If that's the case, how long can it go on? I'm not a hedge fund manager or an economist or anyone else with any sense at all when it comes to macroeconomics, but it seems to me that ultra-low interest rates for extended periods of time could be dangerous.

What about European central banks with negative interest rates? What are, for example, German income investors and fund managers doing with their money right now? Are they investing in German bonds? US Treasuries, for the better yield? Or do they also think 1.7 percent is not sufficient, and therefore gravitate toward equities? I really don't know, so I throw out these questions to the board.