Investigating the Dynamics of Inflation Stability in Iran: An Application of MS-ARFIMA Generalized Nonlinear Approach

One of the challenges for monetary policymakers is how to adopt monetary policy when inflation is persistence. Inflation stability is in fact a measure of the tendency of the inflation rate to maintain its current state and in a way indicates the stickiness in the variable. The issue of inflation stability becomes more difficult when in an economy, inflation stability changes at different times. Therefore, in this study, the intensity of inflation persistence and its dynamics in the Iranian economy were examined using monthly data for the period 1383:1 -1399:6 and using the generalized MS- ARFIMA model. The results showed that in the regime with low inflation and less fluctuations, there is stability of inflation; however, in the regime with high inflation and high fluctuations, there was no evidence of inflation. From an economic and monetary policy perspective, this result is very important. In fact, these results indicate that the monetary policymaker can reduce the level of inflation and return it to its previous values (long-term average) by inflicting a negative shock, quickly and without showing the resistance variable. But when we see moderate inflation in the country's economy, the reduction of inflation will not be easy and usually there will be a need for more efforts to reduce it. Therefore, paying attention to these results can prevent the inconsistency of time in the adoption of monetary policy. It can also be a warning to policymakers to refrain from adopting policies that have limited positive effects in the short term but negative effects in the long run.