# ordAveEffPlot: Plot Average Effects of Variables in Proportional Odds... In DAMisc: Dave Armstrong's Miscellaneous Functions

## 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

 ```1 2``` ```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.

## Author(s)

Dave Armstrong (UW-Milwaukee, Department of Political Science)

## 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

 ```1 2 3 4``` ```library(MASS) data(france) polr.mod <- polr(vote ~ age + male + retnat + lrself, data=france) ## Not run: ordAveEffPlot(polr.mod, "lrself", data=france) ```

DAMisc documentation built on May 30, 2017, 8:12 a.m.