| The Phillips curve has always been a classic topic in the field of macroeconomics.It systematically depicts the relationship between inflation and output in the same direction,which provides an important theoretical basis for macroeconomic situation analysis,economic downside risk warning,and economic recovery policy design.However,since the global financial crisis in 2008,successive bottoming out economic growth and severe structural inflation have frequently coexisted.A series of facts have challenged the validity of the Phillips curve.Many studies have even concluded that the Phillips curve has undergone structural changes.change,the curve exhibits a“flattening” characteristic.But what is interesting is that in the process of economic recovery after the new crown epidemic in 2020,the coexistence of “high growth rate and high prices” appeared again in many countries in the world,which seemed to indicate that the Phillips curve “recovered” again.Then,what are the characteristics of the Phillips curve is an important issue that we need to seek and discuss urgently.Based on the research background,this paper selects the real GDP data from the first quarter of 1995 to the fourth quarter of 2021,and creates a set of economic facts fitting ability test,stationarity test,coupling test,prediction ability test and measurement stability.The output gap measurement and evaluation system tested,using the output gap that is most suitable for China’s actual production gap to estimate the Phillips curve model,according to which to identify the impact of the selection of inflation variables and model setting on the estimation of the Phillips curve model,and at the same time The static characteristics of the Phillips curve are examined.Subsequently,in order to comprehensively,intuitively and dynamically observe the change trend of the “inflation-output” response coefficient in the Phillips curve model,this paper extends the static linear model to the Phillips curve model with time-varying parameters,and further explores the role of the Phillips curve.Condition and applicability of features.The research results show that: first,measurement bias can easily lead to false results of the Phillips curve characteristic test,because the measurement methods of various output gaps and the model setting form of the Phillips curve are based on the economic environment at that time.Therefore,for the current China,it is necessary to carry out a comprehensive measurement evaluation,so as to select the optimal Phillips curve model setting method;second,the Kalman gap is most suitable for China’s Phillips curve characteristic test,In contrast,the capability attributes of the BK gap and the CF gap are weak,the prediction ability and measurement stability of the HP gap are insufficient,and the wavelet gap cannot accurately fit the typical economic events in China;thirdly,the GDP considering the price of investment goods The deflator is more suitable for measuring the level of inflation,and from the perspective of model setting,the "inflation-output" coefficient estimated by the traditional Phillips curve model is the steepest,while the mixed Phillips curve model is more suitable for inflation forecasting;Fourth,from the dynamic calculation results of the time-varying parameter Phillips curve model,it is found that the Phillips curve is often active in periods of relatively violent economic fluctuations,and its function in the stable period of the economy is relatively vague.The policy design in the period of capturing and economic recovery can play the best role,and our understanding of the Phillips curve provides new empirical evidence and factual reference. |
