2004 Election: did income influence voting?
I have been meaning to look at George Megalogenis‘ data tables for some time. Rather than use the data to predict what might happen this year, I thought I would look at the extent to which electorate income explained the 2004 election outcome.
First, however, a couple of box-plots to get a feel for the data.


And now let’s look at the graph that surpised me. The next scatter-plot suggests absolutely no relationship between the median income wihtin in a seat and the Coalition’s two-party preferred vote from that seat. Just look at the R

Why is it so? Well it appears that moderate correlations exist within inner metropolitan, outer metropolitan and provincial seats. That trend suggests that seats with a higher median income are more likely to favour the Coalition. When you get rural seats, many have very low median incomes, but almost all favour the Coalition.




Update: Andrew Leigh sent the following missive …
Dear Bryan,
I noticed your post yesterday on electorate income and voting. As you know, I’m a great fan of yours, and link to you regularly (it should be more often, in fact). However, I do think you’re making a bad mistake in ignoring the ecological fallacy here. The best evidence of this is the research by Glaeser & Sacerdote that finds that income is positively correlated with voting Republican on an individual level, but negatively correlated with Republican voting across US states (http://andrewleigh.com/?p=1419).
Given that we have very good information about the individual-level relationship between income and voting in Australia (eg. my own work, or that of Goot & Watson in a recent AJPS), I’m puzzled as to what you think we can learn from the aggregate-level stuff. You, of course, know all about the ecological fallacy, but I’m worried that some of your readers may be misled.
Politically, this plays into the muddle-headed argument that the Libs make from time to time: that they’re just as much the party of the poor as the ALP. That’s simply a lie.
Cheers,
Andrew.