micEcon (version 0.1-3)

aidsEla: Elasticities of the AIDS model

Description

Calculates the demand elasticities of an AIDS model.

Usage

aidsEla( coef, W, P = NULL, formula = "AIDS",
      qNames = NULL, pNames = NULL )

Arguments

coef

a list containing the coefficients alpha, beta and gamma.

W

a vector of the shares at which the elasticities should be calculated.

P

a vector of the prices at which the elasticities should be calculated.

formula

the elsticity formulas to be used (see details).

qNames

an optional vector of strings containing the names of the quantities to label elasticities.

pNames

an optional vector of strings containing the names of the prices to label elasticities.

Value

• a list containing following elements:
• formula
  the elasticity formula used to calculate these elasticities
• exp
  vector of expenditure elasticities
• marshall
  matrix of Marshallian (uncompensated) price elasticities
• hicks
  matrix of Hicksian (compensated) price elasticities

Details

At the moment only the elasticity formulas of the orginal AIDS ('AIDS'), the formula of Chalfant (1987) ('Ch') and the formula of Eales and Unnevehr (1988) ('EU') are implemented.

References

Chalfant, J.A. (1987) A Globally Flexible, Almost Ideal Demand System. Journal of Business and Economic Statistics, 5, p. 233-242.

Deaton, A.S. and J. Muellbauer (1980) An Almost Ideal Demand System. American Economic Review, 70, p. 312-326.

Eales J.S. and L.J. Unnevehr (1988) Demand for beef and chicken products: separability and structural change. American Journal of Agricultural Economics, 70, p. 521-532.

See Also

aidsEst

Examples

data( Blanciforti86 )
   estResult <- aidsEst( c( "pFood1", "pFood2", "pFood3", "pFood4" ),
      c( "wFood1", "wFood2", "wFood3", "wFood4" ), "xFood",
      data = Blanciforti86, method = "LA:L" )
   wMeans <- colMeans( Blanciforti86[ , c( "wFood1", "wFood2",
      "wFood3", "wFood4" ) ] )
   aidsEla( estResult$coef, wMeans, formula = "Ch" )