micEcon (version 0.6-12)

translogCalc: Calculate dependent variable of a translog function

Description

Calculate the dependent variable of a translog function.

Usage

translogCalc( xNames, data, coef, shifterNames = NULL, dataLogged = FALSE  )

Arguments

xNames

a vector of strings containing the names of the independent variables.

data

dataframe containing the data.

coef

vector containing all coefficients: if there are n exogenous variables in xNames and m shifter variables in shifterNames, the n+1 alpha coefficients must have names a_0, ..., a_n, the n*(n+1)/2 beta coefficients must have names b_1_1, ..., b_1_n, ..., b_n_n, and the m delta coefficients must have names d_1, ..., d_m (only the elements of the upper right triangle of the beta matrix are directly obtained from coef; the elements of the lower left triangle are obtained by assuming symmetry of the beta matrix).

shifterNames

a vector of strings containing the names of the independent variables that should be included as shifters only (not in quadratic or interaction terms).

dataLogged

logical. Are the values in data already logged?

Value

A vector containing the endogenous variable. If the inputs are provided as logarithmic values (argument dataLogged is TRUE), the endogenous variable is returned as logarithm; non-logarithmic values are returned otherwise.

See Also

translogEst and translogDeriv.

Examples

   data( germanFarms )
   # output quantity:
   germanFarms$qOutput <- germanFarms$vOutput / germanFarms$pOutput
   # quantity of variable inputs
   germanFarms$qVarInput <- germanFarms$vVarInput / germanFarms$pVarInput
   # a time trend to account for technical progress:
   germanFarms$time <- c(1:20)

   # estimate a Translog production function
   estResult <- translogEst( "qOutput", c( "qLabor", "land", "qVarInput", "time" ),
      germanFarms )

   translogCalc( c( "qLabor", "land", "qVarInput", "time" ), germanFarms,
      coef( estResult ) )
   #equal to estResult$fitted