A very good point from Dan Drezner

Quiggin thinks he’s only writing about the failure of free-market ideas, but he’s actually describing the intellectual life cycle of most ideas in political economy. All intellectual movements start with trenchant ways of understanding the world. As these ideas gain currency, they are used to explain more and more disparate phenomena, until the explanation starts to lose its predictive power. As time passes, the original ideas become obscured by ideology, caricature and ad hoc efforts to explain away emerging anomalies. Finally, enough contradictions build up to crash the paradigm, although current adherents often continue to advance the ideas in zombielike form. Quiggin demonstrates with great clarity how this happened to the Chicago school of economics. How he can think it won’t happen with whatever neo-Keynesian model emerges is truly puzzling.

Whether this applies to the Quiggin book is beside my point (I read an earlier draft of the manuscript but not the final).  It is in any case a valuable observation and John Quiggin discusses it here.  Drezner's full review, which covers a number of books, is here.