# margEff.censReg: Marginal Effects in Censored Regression Models In censReg: Censored Regression (Tobit) Models

## Description

The `margEff` method computes the marginal effects of the explanatory variables on the expected value of the dependent variable evaluated. Please note that this functionality is currently not available for panel data models.

## Usage

 ```1 2 3 4 5 6``` ```## S3 method for class 'censReg' margEff( object, xValues = NULL, calcVCov = TRUE, returnJacobian = FALSE, ... ) ## S3 method for class 'margEff.censReg' summary( object, ... ) ```

## Arguments

 `object` argument `object` of the `margEff` method must be an object of class `"censReg"` (returned by `censReg`); argument `object` of the `summary` method must be an object of class `"margEff.censReg"` (returned by `margEff.censReg`). `xValues` vector that specifies the values of the explanatory variables (including the intercept if it is included in the model), at which the marginal effects should be calculated. The number and order of the elements of this vector must correspond to the number and order of the estimated coefficients (without sigma). If this argument is `NULL` (or not specified), argument `xValues` is set to the mean values of the explanatory variables. `calcVCov` logical. If `TRUE`, the approximate variance covariance matrices of the marginal effects is calculated and returned as an attribute (see below). `returnJacobian` logical. If `TRUE`, the Jacobian of the marginal effects with respect to the coefficients is returned as an attribute (see below). `...` currently not used.

## Value

`margEff.censReg` returns an object of class `"margEff.censReg"`, which is a vector of the marginal effects of the explanatory variables on the expected value of the dependent variable evaluated at the mean values of the explanatory variables. The returned object has an attribute `df.residual`, which is equal to the degrees of freedom of the residuals.

If argument `calcVCov` is `TRUE`, the object returned by `margEff.censReg` has an attribute `vcov`, which is a the approximate variance covariance matrices of the marginal effects calculated with the Delta method.

If argument `returnJacobian` is `TRUE`, the object returned by `margEff.censReg`has an attribute `jacobian`, which is the Jacobian of the marginal effects with respect to the coefficients.

`summary.margEff.censReg` returns an object of class `"summary.margEff.censReg"`, which is a matrix with four columns, where the first column contains the marginal effects, the second column contains the standard errors of the marginal effects, the third column contains the corresponding t-values, and the fourth columns contains the corresponding P values.

## Author(s)

Arne Henningsen

`censReg`, `coef.censReg`, and `summary.censReg`

## Examples

 ```1 2 3 4 5 6 7``` ```## Kleiber & Zeileis ( 2008 ), page 142 data( "Affairs", package = "AER" ) estResult <- censReg( affairs ~ age + yearsmarried + religiousness + occupation + rating, data = Affairs ) margEff( estResult ) summary( margEff( estResult ) ) margEff( estResult, xValues = c( 1, 40, 4, 2, 4, 4 ) ) ```

### Example output

```Loading required package: maxLik

Please cite the 'maxLik' package as:
Henningsen, Arne and Toomet, Ott (2011). maxLik: A package for maximum likelihood estimation in R. Computational Statistics 26(3), 443-458. DOI 10.1007/s00180-010-0217-1.

If you have questions, suggestions, or comments regarding the 'maxLik' package, please use a forum or 'tracker' at maxLik's R-Forge site:
https://r-forge.r-project.org/projects/maxlik/

Please cite the 'censReg' package as:
Henningsen, Arne (2017). censReg: Censored Regression (Tobit) Models. R package version 0.5. http://CRAN.R-Project.org/package=censReg.

If you have questions, suggestions, or comments regarding the 'censReg' package, please use a forum or 'tracker' at the R-Forge site of the 'sampleSelection' project:
https://r-forge.r-project.org/projects/sampleselection/
age  yearsmarried religiousness    occupation        rating
-0.04192089    0.12953651   -0.39417189    0.07621840   -0.53413656
Marg. Eff. Std. Error t value  Pr(>|t|)
age            -0.041921   0.018444 -2.2728   0.02339 *
yearsmarried    0.129537   0.031168  4.1561 3.713e-05 ***
religiousness  -0.394172   0.093379 -4.2212 2.811e-05 ***
occupation      0.076218   0.059472  1.2816   0.20049
rating         -0.534137   0.094896 -5.6286 2.802e-08 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
age  yearsmarried religiousness    occupation        rating
-0.02982223    0.09215139   -0.28041119    0.05422125   -0.37998110
```

censReg documentation built on May 31, 2017, 1:36 a.m.