Testing for Multiple Bubbles in Inflation for Pakistan

Detection of bubbles in financial markets is an issue of great importance as these split an enduring impact to every sector of the economy leading to substantial losses. In Pakistan, price level has seen abrupt changes which hurts the economic efficiency whereas inflation rates are usually high. So, it is important to detect bubbles present in inflation to have a check whether the hike in inflation is demand driven or there is a prevailing price exuberant behavior that results in sudden boom in inflation. There are very limited studies on detecting bubbles in inflation series for Pakistan. So, the present study takes a lead and address this very important issue by making use of recently developed state of art GSADF approach proposed by Phillips et al. (2015). The empirical analysis is based on five different series which cover inflation rates such as consumer price index (CPI) for the general, the food and the non-food items, the sensitive price index (SPI) and the wholesale price index (WPI). This approach is best suited for testing multiple bubbles as opposed to earlier methods that are designed to test for the presence of only a single bubble in any time series. The empirical findings based on monthly time series data from Jan 2006 to Jan 2019 confirm the existence of multiple bubbles in WPI and CPI non-food. However, for rest of three series, only single bubble has been witnessed. The analysis from the date stamping of bubbles reveal that all bubbles arise during the global financial crisis of 2008 which triggered oil prices resulting in domestic currency depreciation. Some important policy implications are discussed as well.