Changes in macroeconomic conditions. After the introduction of the established monetary policy, it is necessary to maintain certain stability and continuity, which cannot be achieved overnight. During this period, if there is an accident in the economy, it is difficult to make corresponding adjustments to monetary policy, and the effect of monetary policy may decline or even fail, thus generating political pressure from vested interests. The implementation of monetary policy may affect the vested interests of some classes, groups, departments or places, and this subject will react strongly, forming pressure and forcing the adjustment of monetary policy. Time lag of monetary policy: cognitive time lag, decision-making time lag, external time lag, reasonable expectation, other factors: objective economic conditions, political factors, etc.