An enjoyable, reliable and wide-ranging guide to how to scale ideas. The book includes a lot of economic lessons applied to questions like how to scale a business, a nonprofit, or a policy response. Most of these are familiar to students of economics and psychology but it is their application that is most interesting, including ideas like the dangers of false positives, generalizing from non-representative samples, lack of spillovers and economies of scale, and the importance of thinking on the margin.

What sets the book apart, like John Lists's work, is that it is relentlessly empirical throughout. It takes the economic and psychological concepts but brings them to the data in ways that often end up surprising List including questions like do equal opportunity job advertisements help recruit underrepresented minorities, does paying a higher wage necessarily elicit more effort, and will Lyft membership plan's increase its profits.

In addition, there are a wide range of practical examples, many of which List was directly involved in, including setting up a preschool, working for Uber and Lyft, consulting with governments on tax evasion, with Chrysler on wellness, etc. In almost all of them theory helps to guide the thinking but it is really experiments and feedback that are most critical.

I also enjoyed getting to know List a little through the book. It begins with a dedication to his eight! children (talk about scale). It discusses how he got into economics (he came from a family of truckers, got into college on a golf scholarship, did his PhD and Wyoming, and got one job offer out of the 150 he applied for--but then eventually ended up at the University of Chicago), and a lot of the ways he integrates empiricism into the issues he also cares about (like charity and public policy).

Highly recommended.