OLG모형을 이용한 고령화와 물가분석

Most advanced countries have undergone the population ageing. Many empirical studies show that there is close relationship between the population ageing and inflation. This paper is also to study the relationship between the population aging and the inflation. Our study, however, focuses on the theoretical relationship instead of the empirical approaches. In addition, we forecast the long run price level of Korea by using our theoretical model. Our research is based on the Fedotenkov (2016) which is the Post-Keynesian model. Since we set up the model in the framework of the Post-Keynesian, the money supply is the endogenous variable while the interest rate becomes the exogenous variable. This is one of the advantage combining with stochastic model. Our model is combined with the stochastic interest rate model and the rational expectation hypothesis on inflation. We analyze the relationship between inflation with the several important economic variables such as interest rate, survival rate, and population growth, and the default rate. First, we estimate the most of parameters by using the economic data and second, simulate our model from the estimated data as the basic parameter values. In particular, the parameters in Vasicek interest rate model are estimated from the Kalman filter technique. The simulation results of the model presented show that the decrease in population growth and increase in survival rates generally affect the decline of prices. From the results of the simulations, the interest rate turns out to be the most important variable affecting the inflation in our model. Unlike the general logic of relationship between interest rates and inflation, however, the increase in interest rates increases prices, which is similar to recent NFH (Neo Fisherian Hypothesis) claims that an increase in interest rates causes the increase in inflation. Although our model is not based on NFH, the model in this paper is seemed to be proper to reflect the recent economic phenomena. In addition, we also forecast the long term inflation in Korea by using the calibration method. The results of the long term forecasting the price level in Korea demonstrate that aging and declining population growth will have a small effect on decreasing price. This is maybe due to the effects of other economic factors.