The Floor and Multiplier construction usually represents a decaying exponential, starting from 1 in the Base Period, falling to the Floor as time increases. It is commonly used to specify normalised data, such as Cost Indices and Running Cost Trends; but can also be used to generate a trend which rises to the Floor. A Floor and Multiplier is equivalent to a fixed component, Constant = f, plus a variable component, a complementary Exponential Growth with b = 1 – f.
Floor
The fixed component, usually between 0 and 1. The asymptotic value of the time series if the Multiplier is less than 1.
Default: 0.0.
Multiplier (1)
An amount which multiplies the previous year’s value in each year. A value of 1.05 represents 5% annual growth, while a value of 0.95 represents a 5% decline. The Multiplier parameter must be positive, and no greater than 2.
For a Floor, the Multiplier indicates how fast the curve converges to the specified Floor. A lower value will create a steep decline towards the Floor in the early years.
Default: 1.0.
Base Period
Specifies a particular period when the Base value should apply. This can be a year, a quarter, a month, or even a fully-qualified date.
Default: Y0.
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