oil field work With the development of social division of labor and market economy, the concept of market is also developing and deepening, and the multiple meanings of different levels are reflected in the deepening of the project. Most western interest-rate determinism focuses on the analysis of supply and demand comparisons, arguing that interest rates are a price. The difference lies in what supply and demand determines interest rates. For example, Marshall's real interest rate theory emphasizes the real factors of non-monetary factors - productivity and the role of economy in determining interest rate decisions. Productivity is expressed by marginal propensity to invest, and the marginal propensity to save is expressed.