There are good reasons to think that these developments have made the financial system more resilient to shocks originating in the real economy and have made the economy less vulnerable to shocks that start in the financial system. Borrowers have a greater variety of credit sources and are less vulnerable to the disruption of any one credit channel; risk is dispersed more broadly to people who are most willing to hold and manage it. One can see the effects of these changes in the reduced incidence of financial crises in recent years. From the 1970s through the early 1990s, we seemed to be in almost continuous crisis mode. These crises were centered on depository institutions, and because borrowers were so dependent on depository institutions for credit availability, problems at depository institutions meant problems for the financial system and for the economy more generally.
...
But we certainly should not read this experience as meaning that we are free of systemic risk--the risk of financial-sector problems spilling into the real sector or aggravating already difficult economic circumstances. Indeed, I see several reasons for carefully considering the potential for such problems to emerge.
New players and new instruments have become important since 2002, when the last adverse credit cycle peaked. New and already existing market participants are maneuvering for greater shares in a rapidly evolving market structure. Although leverage has declined in the nonfinancial businesses whose credit is being priced and traded, it may well have increased in the structure of intermediary finance. In any event, the growth of tranched CDOs and other structured credit products with substantial embedded leverage has made it more difficult to assess the degree of leverage of individual institutions or of the financial system as a whole.
In addition, the extraordinarily rapid growth of credit derivatives markets in the past few years has occurred against the backdrop of relatively benign macroeconomic performance--good global growth, low inflation, historically high corporate profits and low business failures, and reasonably predictable monetary policies. Partly as a consequence, the prices of financial assets seem to embody relatively low expected volatilities and relatively little reward for taking credit risk or for extending the duration of investor portfolios.