wtp.gmnl {gmnl} | R Documentation |
Compute Willingness-to-pay
Description
Compute the willingness-to-pay.
Usage
wtp.gmnl(object, wrt = NULL, digits = max(3, getOption("digits") - 2))
Arguments
object |
an object of class |
wrt |
a string indicating the variable with respect to which the WTP is computed, |
digits |
number of significant digits to be used for most numbers. |
Details
For each coefficient, this function computes both the point estimate and standard error of WTP with respect to the variable specified in the argument wrt
. Specifically, let \beta_k
be the coefficient for variable k
, then
WTP_{k}=-\beta_k/\beta_p
where \beta_p
is the coefficient for the variable specified with the argument wrt
. Note that, wtp.gmnl
does not include the negative sign.
wtp.gmnl
function is a wrapper for the deltamethod
function of the msm package.
Value
A coefficient matrix with the WTP point estimates and standard errors.
Author(s)
Mauricio Sarrias.
References
Greene, W. H. (2012). Econometric Analysis, Seventh Edition. Pearson Hall.
Train, K. (2009). Discrete Choice Methods with Simulation. Cambridge University Press.
See Also
deltamethod
for the estimation of the standard errors.
Examples
## Examples using the Electricity data set from the mlogit package
library(mlogit)
data("Electricity", package = "mlogit")
Electr <- mlogit.data(Electricity, id.var = "id", choice = "choice",
varying = 3:26, shape = "wide", sep = "")
## Estimate a conditional logit model
clogit <- gmnl(choice ~ pf + cl + loc + wk + tod + seas| 0,
data = Electr)
wtp.gmnl(clogit, wrt = "pf")