base period

Base period

A particular period of time used for comparative purposes when measuring economic data.

---

Base Period

The period of time against which an index is measured. For example, suppose the base period is 2001 and the initial value of an index is 100. If the index is 150 in 2009, it means that the value of the index is 50% higher in 2009 than it was in 2001. It is also called the reference period.

---

base period

The time or period of time on which an index is based. Usually, the index is established at a value of 10 or 100 in the base year. The consumer price index of 177 in early 2002 indicated that consumer prices were 77% higher than during the base period of 1982-84. The Standard & Poor's 500 Stock Index of 1300 in early March 2002 indicated that, on average, a portfolio of blue chip stocks with a market value of $10 during the period 1941-43 (the base period) had a market value of $1,300 in early 2002. The portfolio of stocks making up the S&P 500 underwent substantial changes during the intervening years.

---

base period

The point in time that serves as a reference for calculating financial and economic data.The base period value is usually set at 1.0 or 100, called the benchmark, for purposes of comparison,and then all other periods are either greater or less than the benchmark.