The Base effect relates to inflation in the corresponding period of the previous year, if the inflation rate was too low in the corresponding period of the previous year, even a smaller rise in the Price Index will arithmetically give a high rate of inflation now.
A smaller rise in the Price Index will arithmetically give a high rate of inflation now. This is what the Base effect relates to inflation in the corresponding period of the previous year. The inflation rate was too low in the corresponding period of the previous year. This was even.