Some good thoughts on this topic I read recently:
* Quantative Easing (eg printing money) floods the economy with money, it has go somewhere.
* Since the real economy (manufacturing &#x2F; information) isn&#x27;t growing, the money flows into assets (eg real estate or stock bubbles)
* When there&#x27;s zero interest, it exacerbates the problem, because if you&#x27;ve got capital, it&#x27;s impossible to find anywhere to invest it to get a return. Hence you&#x27;re incentivised to put it into assets. 
* Basically you&#x27;re not seeing assets (houses&#x2F;stock) going <i>up</i> in value, you&#x27;re seeing money go <i>down</i> in value. It&#x27;s basically out-of-control inflation, it&#x27;s just that the inflation isn&#x27;t spread evenly yet.<p>Disclaimer: These aren&#x27;t my ideas, i&#x27;m merely parroting. But i thought they were clever and worth sharing.