Are potential "asset-price bubbles" always dangerous?

En un artículo publicado en Financial Times Frederic Mishkin identifica dos tipos de asset-bubbles: "pure irrational exuberance bubble" (Mild) y "a credit boom bubble" (Severe). Las burbujas del segundo tipo (feedback loop) presentan las siguientes características:

"[…] exuberant expectations about economic prospects or structural changes in financial markets lead to a credit boom. The resulting increased demand for some assets raises their price and, in turn, encourages further lending against these assets, increasing demand, and hence their prices, even more, creating a positive feedback loop. This feedback loop involves increasing leverage, further easing of credit standards, then even higher leverage, and the cycle continues. [...] Eventually, the bubble bursts and asset prices collapse, leading to a reversal of the feedback loop."

A diferencia de la perspectiva de Dr. Doom, Mishkin señala que:

"But if bubbles are a possibility now, does it look like they are of the dangerous, credit boom variety? At least in the US and Europe, the answer is clearly no. Our problem is not a credit boom, but that the deleveraging process has not fully ended. Credit markets are still tight and are presenting a serious drag on the economy."
Source: FT.com