Keane and related articles on this issue are here (ECONOM_3232)
Comments on Keane are also attached feb8, Keane comments
This paper is related:
Nonadditive Models with Endogenous Regressors ∗
Guido W. Imbens†
Lots of good material on Instrumental Variables in Freedman Chapter 7 Statistical Models -- need to write this up
Also, writeup of RODRIK: Why we cannot make policy conclusions from cross country regressions.