In 2000, George Akerlof and Rachel Kranton published Economics and Identity in the Quarterly Journal of Economics proposing a way on how to acknowledge the influence of identity in the standard economic framework. The published paper was surprisingly non-technical, it focused rather on empirical examples that are consistent with their model than on theoretical derivations, i. e. the rigorous use of mathematics to obscure any intuition one might have. Their book Identity Economics follows in the same tradition. It is basically an accessible summary of their papers on the topic that they published so far. In a number of chapters they present first the intuition of their model and than some applications by enumerating a long list of empirical observations that are consistent with their model.

This style of presentation is both fortunate and unfortunate. It is fortunate because the book becomes consequently accessible to a non-economist audience. Though I doubt that a lay-person may actually be interested in how economists deal with the influence of identity on economic decision making and in the fact that they (the economists) did not care to do so previously. After all, identity is not really a new concept. Ask a sociologist or psychologist about this… Therefore, the general style and choice of content of the book is also unfortunate. The actual audience may rather consist of economist and researcher from fields that have acknowledged identity as an important factor long ago. This audience – and here I include myself – is certainly also interested in the underlying math. A technical appendix would have been nice. Luckily, Rachel Kranton published some material (an earlier, more technical version of their paper Identity and the Economics of Organizations) on her webpage.

In a nutshell, identity determines the optimal choice for someone belonging to a certain identity class. If the individual deviates from this “class action” her individual utility is reduced. Hence, utility is just the sum of the standard utility and an identity penalty term. The problem, of course, is then to define identity categories, to define the optimal “class action”, to assign an individual to such a category, and to determine the appropriate penalty.

All in all, the whole approach is rather interesting. I like that the individual is finally put into a (social) context. It certainly enhances the descriptive power of the standard model. Its prescriptive power is, however, rather ambiguous. There are too many unknowns. Consequently, the general reception of these ideas in economics seems rather lukewarm (as already noted in another review at whimsley worth reading). Nevertheless, others are picking up on the topic. There will be, for instance, another book on it published this winter by Cambridge University Press: Individuals and Identity in Economics authored by John B. Davis that seems rather interesting as it promises a more broader overview and also some more rigorous illustrations.