translogCheckCurvature {micEcon}R Documentation

Curvature of a Translog Function

Description

Check curvature of a translog function.

Usage

translogCheckCurvature( xNames, data, coef, convexity = TRUE,
   quasi = FALSE, quadHalf = TRUE, dataLogged = FALSE, ... )

## S3 method for class 'translogCheckCurvature':
print( x, ... )

Arguments

xNames a vector of strings containing the names of the independent variables.
data dataframe containing the data.
coef vector containing all coefficients.
convexity logical. Check whether the function is (quasi)convex (default, TRUE) or (quasi)concave (FALSE).
quasi logical. Check whether the function is quasiconvex/quasiconcave (TRUE) or convex/concave (default, FALSE).
quadHalf logical. Multiply the quadratic terms by one half?
dataLogged logical. Are the values in data already logged?
x an object returned by translogCheckCurvature.
... arguments passed from translogCheckCurvature to semidefiniteness (if argument quasi is FALSE), quasiconvexity (if arguments convexity and quasi are both TRUE), or quasiconcavity (if argument convexity is FALSE and quasi is TRUE). Further arguments to print.translogCheckCurvature are currently ignored.

Value

translogCheckCurvature returns a list of class translogCheckCurvature containing following objects:

obs a vector indicating whether the condition for the specified curvature is fulfilled at each observation.
convexity argument convexity.
quasi argument quasi.

Author(s)

Arne Henningsen

See Also

translogEst and translogCheckMono

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 )

   # check whether the production function is quasiconcave
   translogCheckCurvature( c( "qLabor", "land", "qVarInput", "time" ),
      germanFarms, coef( estResult ), convexity = FALSE, quasi = TRUE )

[Package micEcon version 0.5-14 Index]