Reference Base Period A year in which the Consumer Price Index is equal to 100, a reference base period that serves as a benchmark for future periods, allowing economists to judge levels of inflation. Currently, the reference base period is set between 1982 and 1984. Investopedia Says: When a year is assigned a price level from the CPI, the reference base period can be used to convey how much inflation occurred. For example, if the current year has a CPI level of 115, this would mean that prices today have increased by 15% (115-100) from the base period of 1982-1985. Related Terms: Constant Dollar Consumer Price Index - CPI Economic Indicator Inflation Producer Price Index - PPI |