Wednesday June 20, 2007
My paper with Peter Brent on voter enrollment in Australia just appeared as part of a series of papers published by the Democratic Audit of Australia, a project run out of the Australian National University. Our story is fairly simple: the Australian Electoral Commission has become more proficient at expunging voters from the roll while at the same time changes in legislation have made it tougher to get on and stay on the roll. I reproduce Figure 1 of the paper here (thumbnail below, click for larger version), which shows the relationship between Australia’s ERP (estimated resident population) and the size of the electoral roll. We normalized the two series at 100 around the time of the 2004 election, and it is pretty clear that recent enrollment numbers are lagging behind where they ought to be given the historical relationship with ERP.
Caveat/Gripe: ERP is hardly perfect as a (relative) baseline for assessing under/over-enrollment. That said, unless the age composition of the citizenry and/or the number of immigrants have dramatically changed since the 2004 election, the normalization of enrolments to ERP should have decent over-time validity. What we’d really like is to know the number of eligible voters (basically, adult citizens), but the Australian Bureau of Statistics doesn’t publish such a time series, although the AEC does appear to request and obtain such a number from the ABS when AEC conducts internal audits of how well Continuous Roll Update (CRU) is faring. ABS does report the number of adult citizens with each Census, and we’re expecting a June 2006 number next week with the release of the 2006 Census, so expect a quick, minor update of the paper.