Comparing CCES Validated Turnout vs. Actual Turnout (Update)

Last year, I blogged about bias in the CCES’s validated turnout estimates — how much they were over- or under-estimating the true turnout rate. However, I used the voting eligible population (VEP) as the denominator in the calculation of actual turnout, whereas the best comparison for rates from a survey like the CCES — that covers all adults — ought to use the voting age population (VAP) as the denominator (thanks to Shiro Kuriwaki for pointing this out). Below are recalculated state-level bias plots that use VAP turnout as the “actual turnout” comparison. I also add on validated turnout from the 2018 CCES.

ccesturnoutbias_Midwest_2019-12-31.png

ccesturnoutbias_West_2019-12-31.png

ccesturnoutbias_Northeast_2019-12-31.png

ccesturnoutbias_South_2019-12-31

One quicker (and likely better) way of summarizing these results is through a CCES vs. actual turnout by year small multiple graph, with a 45-degree line indicating over and under-estimates. I show that below, where the key takeaway — the validated CCES turnout more closely matching actual turnout over time — becomes clearer.

cces-vap-45degree_2019-12-31

Comparing CCES Validated Turnout vs. Actual Turnout (Update)