summary {sfadv}

Summary method for object of class “sfaendog”

Description

It creates and displays the results of an estimation returned by sfaendog.

Usage

## S3 method for class 'sfaendog'
summary(object, all = FALSE, ...)

## S3 method for class 'summary.sfaendog'
print(x, digits = max(3, getOption("digits") - 3), 
     signif.stars = getOption("show.signif.stars"), ...) 

Arguments

object

An object of class ⁠'sfaendog'⁠ returned by the function sfaendog.

x

An object of class ⁠'summary.sfaendog'⁠ returned by the function summary.

all

Logical. If FALSE (default), only ‘Step1’ results, Fisher test results for the strength of external instrumental variables, and ‘Step4’ results are returned.
If all = TRUE, summary of all ‘Steps’ in sfaendog are returned.

signif.stars

Logical. If TRUE, significance stars are printed.

digits

The minimum number of significant digits to be printed in values.

...

Currently not used.

Details

print.summary.sfaendog tries to be smart about formatting the coefficients, standard errors, etc. and additionally gives significance stars if signif.stars is TRUE.

Value

A list of class ⁠'summary.sfaendog'⁠ is returned, containing the number of observations, the parameter estimates, standard errors, t-values and p-values.

More precisely:

Step1

The list of summary statistics of ‘Step1’ OLS estimation of the endogenous input.

FishTest

A list containing the names of the variables used as external instrumental variables in the estimation, and the results (i.e. F-value and Pr(>F)) of the Fisher test on the strength of these external instrumental variables.

Step2

The list of summary statistics of ‘Step2’ NLS estimation of the stochastic frontier production model.

Step3

The list of summary statistics of ‘Step3’ GMM estimation of the stochastic frontier production model. The name of the endogenous input (wrapped with ‘*’) is also returned.

Step4

The list of summary statistics of ‘Step4’ GMM estimation of the stochastic frontier production model. In addition, it also returns the name of the endogenous input (wrapped with ‘*’ in the result table) indicating that the predicted value from Step1 is used.

Step2 and Step3 are returned only if all = TRUE.

In Step2 to Step4 results, InterceptX is the constant term in the production part of the stochastic frontier production model, while InterceptZ is the constant term in the inefficiency effect part.

Information on convergence is also provided with Step3 and Step4 results, where Convergence code = 0 indicates successful completion (see optim).

Author(s)

Yann Desjeux, Laure Latruffe

See Also

sfaendog, for the model fitting function.