aidsCalc: Shares and Quantities of the Almost Ideal Demand System

Description

Given prices, total expenditure and coefficients this function calculates the demanded expenditure shares and quantities based on the Almost Ideal Demand System.

Usage

aidsCalc( pNames, xtName, data = NULL, px = "TL", lnp = NULL,
      coef = NULL, alpha0 = ifelse( is.null( coef$alpha0 ), 0, coef$alpha0 ) )

Arguments

pNames

vector containing the names of the prices.

xtName

name of the total expenditure variable.

data

data frame containing the variables.

prices index (see aidsPx)

lnp

log of the price index.

coef

a list containing the coefficients alpha, beta and gamma.

alpha0

coefficient $\alpha_0$ in the translog price index.

Value

aidsCalc returns a list with following elements:
sharesa data frame containing the calculated expenditure shares
quantitiesa data frame containing the calculated quantites

References

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

Examples

Run this code

data( Blanciforti86 )
   pNames <- c( "pFood1", "pFood2", "pFood3", "pFood4" )
   wNames <- c( "wFood1", "wFood2", "wFood3", "wFood4" )

   ## LA-AIDS
   estResult <- aidsEst( pNames, wNames, "xFood",
      data = Blanciforti86, method = "LA:L" )

   lnp <- aidsPx( "L", pNames, wNames, Blanciforti86 )

   fitted <- aidsCalc( pNames, "xFood", Blanciforti86,
      coef = estResult$coef, lnp = lnp )

   fitted$shares  # equal to estResult$wFitted
   fitted$quant   # equal to estResult$qFitted

   ## AIDS
   estResult <- aidsEst( pNames, wNames, "xFood",
      data = Blanciforti86, method = "MK:L" )

   fitted <- aidsCalc( pNames, "xFood", Blanciforti86,
      coef = estResult$coef )

   fitted$shares  # equal to estResult$wFitted
   fitted$quant   # equal to estResult$qFitted