Because the function of a book review is to direct busy readers towards good books and away from bad ones, a good book review and a kind book review are often incompatible. This is one of those unfortunate occasions. Even though Richard Day notes promisingly in the preface that “I felt my mission to have been that of providing a better characterization of economic change” (p. x), no economic historian is going to benefit from delving into this book.

The first problem of the book is that it is a book only in the sense that its pages have consecutive numbering. The volume is composed of 12 essays, based mainly on previously published papers and essays written between 1967 and 1998. These essays cohere about as well as the collection of objects you find in the typical California yard sale. Here you can read, in no particular order, essays on both technological changes and sharecroppers in the Mississippi Delta, 1940 to 1957, and on global human development since the origin of the earth. Had Cambridge University Press mixed up the order of the chapters on the way to the printer, only the author would have noticed. Had one of the chapters been deleted by mistake, no purchaser would have been angrily demanding their money back at the bookstore.

The second problem of the book is that even if the reader decided to try applying Day's methods of economic dynamics in economic history, after reading the book they would not have any idea how to do that. It is not a cookbook for the methods of economic dynamics. The examples are laid out at too abstract a level. There is page after page of diagrams, all with time on the horizontal axis, where curves swoop, dive, arc, and ascend like dolphins at play. But where exactly these curves came from is not laid bare. The analogy would be trying to teach people to cook haut cuisine by showing them a list of ingredients and pictures of the final dishes. A model of “Economic Development and Migration” (chapter 8) may highlight the “complexity and interdependence of the building blocks of the economic system and the complex multimode, multiphase structure of development that evolves” (p. 156). But how that complexity is modeled will remain a mystery to the average reader. Even if the mission stated in the preface succeeded and you got the religion, no reader could figure out how to worship the new dynamic god in future academic work.

But average readers, I think, will not be persuaded by the material presented here to abandon their static friends and family and go off in search of dynamism. They will not get “teched up” in Recursive Programming and the other tools of the Economic Dynamist that the new god demands, because Day never actually demonstrates the value added from such techniques. He may be able to predict labor inputs in the Mississippi delta in 1940–1957 using a dynamic model of production (chapter 4), but has he done so any better than alternative static models? That question is not addressed. He models the green revolution in the Punjab in dynamic terms (chapter 5), but again with no reference to any alternative ways of modeling these changes. As with calibration methods in macroeconomics, or computable general equilibrium models in economic history, showing that your model can roughly reproduce the paths observed in the data is not proving that you have produced the final, best description of reality. Theories can only be judged relative to other, competing theories, and this book never considers such alternatives.

Thus sadly while economic dynamics and economic history have many of the same interests and issues, this book largely fails to speak to historians.