The study examines how changes in Japan's monetary policy affect the overall economy. By analyzing data and using a forecasting method, the researchers found that when there is an increase in money supply (M2), the economy grows gradually. However, when interest rates go up, the economy shrinks. These effects reach their peak at a certain point and then fade away over time. This means that Japan's economy responds positively to expansionary monetary policy shocks but negatively to contractionary ones.