See also: Growth, GrowthFromValue, GrowthFromYear


GrowthAs(Branch:Variable) or
GrowthAs(Branch:Variable, Elasticity) or


Calculates a value in any given year using the previous value of the current branch and the rate of growth in another named branch. This is equivalent to the formula:

Current Value(t) = Current Value(t-1) * NamedBranchValue(t)

In the second form of the function, the calculated growth rate is adjusted to reflect an elasticity. More precisely, the change in the current (dependent) branch is related to the change in the named branch raised to the power of the elasticity. This is a common approach in energy modeling, in which the growth in one variable is estimated as a function of the growth in another (independent) variable.



Growth(GDP, 1)

In this example (elasticity = 1), the current branch grows at the same rate as the named branch (GNP).

GrowthAs(GDP, 0.9)

In this example (elasticity = 0.9), the current branch grows more slowly than GNP.

GrowthAs(GDP, 1.2)

In this example (elasticity = 1.2), the current branch grows more rapidly than GNP.

GrowthAs(GDP, 0)

In this example (elasticity = 0), the current branch is constant (i.e. independent of GNP).