受西方宏观经济学追求微观基础的潮流影响，哈恩难题和希克斯共存问题成为长期困挠货币经济学的两大理论难题。
Influenced by the trend of searching micro-foundation for macroeconomics , Hahn 's Problem and Hick 's Coexistence Problem becomes the main two perplexing today 's monetary theories .
哈恩难题