frontierTranslogRay {frontier} | R Documentation |
Translog Ray Frontiers
Description
This is a convenient interface for estimating
translog stochastic ray frontier models
using frontier
.
Usage
frontierTranslogRay( yNames, xNames, shifterNames = NULL,
zNames = NULL, data, ... )
Arguments
yNames |
a vector of two or more character strings containing the names of the output variables. |
xNames |
a vector of strings containing the names of the input variables that should be included as linear, quadratic, and interaction terms. |
shifterNames |
a vector of strings containing the names of the explanatory variables that should be included as shifters only (not in quadratic or interaction terms). |
zNames |
a vector of strings containing the names of the Z variables (variables explaining the efficiency level). |
data |
a (panel) data frame that contains the data
(see documentation of |
... |
further arguments passed to |
Value
frontierTranslogRay
returns a list of class frontierTranslogRay
(as well as frontierQuad
and frontier
)
containing almost the same elements as returned by frontier
.
Additionally, it includes following objects:
distance |
the “distance” from the origin (zero) to the point of the dependent variables. |
theta_i |
the “direction” from the origin (zero)
to the point of the dependent variables
(with |
Author(s)
Arne Henningsen and Geraldine Henningsen
References
Löthgren, M. (1997) Generalized stochastic frontier production models, Economics Letters, 57, 255-259.
Löthgren, M. (1997) A Multiple Output Stochastic Ray Frontier Production Model, Working Paper Series in Economics and Finance, No. 158, Stockholm School of Economics.
Löthgren, M. (2000) Specification and estimation of stochastic multiple-output production and technical inefficiency Applied Economics, 32, 1533-1540.
See Also
Examples
## preparing data
data( germanFarms )
# quantity of crop outputs
germanFarms$qCrop <- germanFarms$vCrop / germanFarms$pOutput
# quantity of animal outputs
germanFarms$qAnimal <- germanFarms$vAnimal / germanFarms$pOutput
# quantity of variable inputs
germanFarms$qVarInput <- germanFarms$vVarInput / germanFarms$pVarInput
# estimate a translog ray production function
estResultRay <- frontierTranslogRay( yNames = c( "qCrop", "qAnimal" ),
xNames = c( "qLabor", "land", "qVarInput" ),
data = germanFarms )
summary( estResultRay )