| quadFuncDeriv {micEcon} | R Documentation |
Calculate the derivatives of a quadratic function.
quadFuncDeriv( xNames, data, allCoef, allCoefCov = NULL, quadHalf = TRUE )
xNames |
a vector of strings containing the names of the independent variables. |
data |
dataframe containing the data. |
allCoef |
vector containing all coefficients. |
allCoefCov |
optional covariance matrix of the coefficients. |
quadHalf |
logical. Multiply the quadratic terms by one half? |
a list of class quadFuncDeriv containing following objects:
deriv |
data frame containing the derivatives. |
variance |
data frame containing the variances of the derivatives
(only if argument allCoefCov is provided). |
stdDev |
data frame containing the standard deviations of the derivatives
(only if argument allCoefCov is provided). |
Arne Henningsen ahenningsen@agric-econ.uni-kiel.de
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$time <- c(1:20)
# estimate a quadratic production function
estResult <- quadFuncEst( "qOutput", c( "qLabor", "land", "qVarInput", "time" ),
germanFarms )
# compute the marginal products of the inputs
margProducts <- quadFuncDeriv( c( "qLabor", "land", "qVarInput", "time" ),
germanFarms, estResult$allCoef, estResult$allCoefCov )
margProducts$deriv