The authors argue that consumer valuations of goods and services are a lot more arbitrary than we may think, and are affected by several 'arbitrary' components and biases. They describe the phenomenon of 'Tom's Law', whereby Mark Twain's Tom Sawyer discovered a great law of human behavior: that in order to make a person covet a thing, it is only necessary to make the thing difficult to attain. They introduce the concept of 'coherent arbitrariness' and show how arbitrariness is enhanced by ambiguity in a good or bad experience.

In the last two decades, Behavioral Economics (the importation of ideas from Psychology to Economics) has become a prominent fixture on the intellectual landscape. In turn, it has spawned the field of 'Neuroeconomics', whereby ideas from Neuroscience are imported into Economics. The study of the human brain and nervous system is beginning to allow for direct measurement of thoughts and feelings; and this, in turn, is challenging our understanding of the relation between mind and action, leading to new theoretical constructs and calling old ones into question. The authors describe the findings to date, covering automatic vs. controlled processes and cognitive vs. affective processes, and their general implications for Economics.