This paper is based on a long-term research program with Rachel Kranton on the implications of identity for economic behavior.Our previous joint papers ( Akerlof and Kranton (2000), ( 2002) and ( 2005)) have explored implications outside of macroeconomics of utility functions dependent on people's notions of what ought to be.Some of this paper-especially Section IV ("Norms: The Missing Motivation") and Section X ("Economic Methodology")-has been directly taken from our joint manuscript: The Missing Motivation: Economics Made Human (Akerlof and Kranton (2006)).I am especially grateful to Professor Kranton for extending to me the invitation to join this project, after she had the initial insight in the spring of 1996 that concerns regarding identity were missing from economic theory.I have also benefitted from conversations with Robert Shiller, with whom I am co-authoring work on behavioral macroeconomics.