translogEla {micEcon} | R Documentation |
Elasticities of a translog Function
Description
Calculate the elasticities of a translog function.
Usage
translogEla( xNames, data, coef, coefCov = NULL,
dataLogged = FALSE )
## S3 method for class 'translogEst'
elas( object, data = NULL, dataLogged = NULL,
... )
Arguments
xNames |
a vector of strings containing the names of the independent variables. |
data |
dataframe containing the data;
if argument |
coef |
vector containing all coefficients:
if there are |
coefCov |
optional covariance matrix of the coefficients:
the row names and column names must be the same as the names
of |
dataLogged |
logical. Are the values in |
object |
object of class |
... |
currently ignored. |
Details
Shifter variables do not need to be specified, because they have no effect on the elasticities. Hence, you can use this function to calculate elasticities even for translog functions that have been estimated with shifter variables.
Value
A data frame containing the elasticities,
where each column corresponds to one of the independent variables.
If argument coefCov
is provided, it has the attributes
variance
and stdDev
,
which are two data frames containing the variances
and the standard deviations, respectively, of the elasticities.
Author(s)
Arne Henningsen
See Also
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$time <- c(1:20)
# estimate a quadratic production function
estResult <- translogEst( "qOutput", c( "qLabor", "land", "qVarInput", "time" ),
germanFarms )
# calculate production elasticities of all inputs
estEla <- translogEla( c( "qLabor", "land", "qVarInput", "time" ),
data = germanFarms, coef = coef( estResult ),
coefCov = vcov( estResult ) )
# all elasticities
estEla
# t-values of all elasticities
estEla / attributes( estEla )$stdDev