Robert Pozen, Chairman of MFS Investment Management, offers an insightful examination of the causes of the current global financial crisis in his new book “Too Big To Save? How to Fix the U.S. Financial System.”  Pozen’s text provides a detailed framework to analyze the abundance of information about the financial crisis, to avoid repeating the mistakes of the past and to create an effective plan for fixing the financial system in the future.  In part one of his book, Pozen lays blame for the collapse of the financial system on the bursting of the U.S. housing bubble.  The bubble, he explains, resulted from excessive debt spread globally by mortgage securitization, which allowed lenders to easily obtain cash to make more loans.  When the mortgages underlying these securities began to default and later reached record highs, even the most conservative investors in mortgage-backed securities suffered heavy losses.  After describing the origins of the financial crisis, Pozen’s book explains in parts two through four: (1) the government’s correct and incorrect decisions in responding to this financial crisis; and (2) the actions it still must take to resolve the financial crisis and prevent its recurrence.  With regard to the latter, he recommends that the least burdensome regulatory strategy would be the government’s best chance of success.  In particular, he suggests that Congress should focus on encouraging financial innovation and on coping with systemic risks, specifically with regard to regulating hedge funds.  We offer a detailed summary and review of Pozen’s book.