ordAveEffPlot {DAMisc} R Documentation

## Plot Average Effects of Variables in Proportional Odds Logistic Regression

### Description

For objects of class polr the function plots the average effect of a single variable holding all other variables at their observed values.

### Usage

ordAveEffPlot(
obj,
varname,
data,
R = 1500,
nvals = 25,
plot = TRUE,
returnInd = FALSE,
returnMprob = FALSE,
...
)


### Arguments

 obj An object of class polr varname A string providing the name of the variable for which you want the plot to be drawn. data Data used to estimate obj. R Number of simulations to generate confidence intervals. nvals Number of evaluation points of the function plot Logical indicating whether or not the result should be plotted (if TRUE) or returned to the console (if FALSE). returnInd Logical indicating whether average individual probabilities should be returned. returnMprob Logical indicating whether marginal probabilities, averaged over individuals, should be returned. ... Arguments passed down to the call to xyplot

### Details

Following the advice of Hanmer and Kalkan (2013) the function calculates the average effect of a variable holding all other variables at observed values and then plots the result.

### Value

Either a plot or a list with a data frame containing the variables

 mean The average effect (i.e., predicted probability) lower The lower 95% confidence bound upper The upper 95% confidence bound y The values of the dependent variable being predicted x The values of the independent variable being manipulated

and the elements Ind or Mprob, as requested.

Dave Armstrong

### References

Hanmer, M.J. and K.O. Kalkan. 2013. ‘Behind the Curve: Clarifying the Best Approach to Calculating Predicted Probabilities and Marginal Effects from Limited Dependent Variable Models’. American Journal of Political Science. 57(1): 263-277.

### Examples


library(MASS)
data(france)
polr.mod <- polr(vote ~ age + male + retnat + lrself, data=france)
## Not run: ordAveEffPlot(polr.mod, "lrself", data=france)



[Package DAMisc version 1.7.2 Index]