Despite beginning with a useful and interesting survey of the history of economic theorizing about the Depression, the majority of this book is taken up with an ill-considered attempt to explain the duration of the Depression as part of a secular move away from old industries (such as textiles and coal) to new (such as automobiles and packaged food). Although the myriad of tables Bernstein provides do show that some industries grew during this dark economic period while many shrank, these divergences hardly explain the lack of overall economic growth or the persistence of unemployment during the 1930s.
In many ways this book demonstrates the classic follies of economic history as it is carried out in history departments. It shows a lack of concern with the work done by typical economists in the field, and has no overarching theoretical framework to explain its causations. In the end, Bernstein tries to resuscitate the discredited theories of Rexford Tugwell, the FDR Brain-Truster who thought the Depression was part of a "disproportionality crisis," that caused some industries to over- or under-invest in their markets. He sought a grand, government-directed, though always elusive, "balance" between all imaginable industrial sectors.
Though this is interesting as part of the intellectual tenor of the era, the ideas themselves are best left in the dustbin of history.