There has been a recent trend in the integration of the methodologies of Theoretical Computer Science and Mathematical Economics. An especially powerful concept is that of bounded rationality, interpreted in the computational resource context. We should explain how it has been applied to introduce the correct solution concept for computaions of fixed point, Nash equilibrium, and Arrow-Debreu general equilibrium, in the differentiation and the unification of those closedly related problems in terms of their computational difficulties.

In the spirit, we discuss an evolution of the solution concepts in understanding the auction mechanisms for Internet sponsored search auctions.

The talk is based on works done with Chen Xi; Du Ye; Bu Tianming and Qi Qi.