In this paper, three fundamental issues of robust control are discussed, which are model uncertainty description, nominal performance, robust stability and robust performance.

Based on the SCP analysis model of Industry Organization technology, the paper points out that the market performance finally depends upon the real market structure, instead of nominal monopolization.

The gap between the performance of inflation and that of nominal GDP is so big that some economists, such as Scott Sumner of Bentley University, are dusting off an old idea.