This volume contains recent surveys of the most important topics in economics.

1. Auctions and efficiency Eric Maskin; 2. Why every economist should learn some auction theory Paul Klemperer; 3. Global games: theory and applications Stephen Morris and Hyun Song Shin; 4. Testing contract theory: a survey of some recent work Pierre-Andre Chiappori and Bernard Salanié; 5. The economics of multidimensional screening Jean-Charles Rochet and Lars A. Stole; Discussion of papers by P. A. Chiappori and B. Salanié and by J.-.C Rochet and L. A. Stole Patrick Legros; 6. Theories of fairness and reciprocity: evidence and economic applications Ernst Fehr and Klaus M. Schmidt; 7. Hyperbolic discounting and consumption Christopher Harris and David Laibson; Discussion of papers by E. Fehr and K. M. Schmidt and by C. Harris and D. Laibson Glenn Ellison; 8. Agglomeration and economic theory Masahisa Fujita and Jacques-Francois Thisse; 9. Non-market interactions Edward Glaeser and Jose A. Scheinkman.