December 6th: updated estimates for the referendum on electoral reform

First of all, a giant thanks to those of you who decided to contribute to the Go Fund Me campaign I started yesterday to get a post-referendum poll. This is amazing. I'll start the poll tomorrow and will keep you updated.

Ok, let's use the most up-to-date turnout data from Elections BC. Turnout is now above the 40% mark (so even BC Liberals leader Andrew Wilkinson would have to recognize this referendum as valid...) while the processed ballots are at 35.4%. It hasn't increased much this week (for the overall turnout based on received ballots). Google Trends was showing a decrease in interest in proportional representation for the last few weeks. I feel that people who wanted to vote did so at this point. With that said, given the potentially small margin (see below), trying to get extra votes tomorrow might be important.

Here is a graph from David P. Ball showing where we stand:



Ok so let's try to estimate who is ahead.

Please remember that all the numbers below are estimates. They are based on demographic, turnout and polling data. They are the best I can do at this point but they are still estimates. I saw people spreading these numbers on social media as if they were hard counts. In particular, if the polls are wrong (for instance if the undecided broke down for the YES or the NO side), then these estimates will be wrong as well.

Method 1: using a mix of age and regional data.

Specifically, using the polling averages by regions (Lower Mainland, Van Island and the Interior) as well as by age (18-34, 35-54, 55+; combined with the turnout by age for 2017).



It has been super stable for a while now. The YES is climbing super slowly but remains behind. In this scenario the YES side would lose be fewer than 25k votes (out of over a million!).

All hope isn't lost for the YES side. Regression-based analysis of the turnout show that the 18-34 are voting far more than last year while the 35-54 are voting a lot less. The 55+ (very much against PR) are also voting less. So while the estimates should already take that into account partially (since more votes are coming from ridings with more voters aged 18-34), it might still be underestimating the YES votes. This could be the case if the 18-34 are voting more everywhere, including in ridings with more 55+. I will try to adjust for this in a future post.


Method 2: using the votes in 2017 (for each party)

In this estimate, I use the polling data by party (percentage of BC Liberals who support PR, etc; I'm using an average of the Research Co. and Angus-Reid polls with a higher weight for the former as it's more recent. If I were to use a straight up average, the YES would be ahead in the graph below). This might actually be the best method as vote patterns might capture a lot of effects, much more than accounting separately for the age and the region. Plus this referendum campaign has ultimately turned very partisan.



This is just insanely close. The difference is 2300 votes!

If I also adjust for the newly registered voters (around 8400) which can reasonably be assumed to have registered more in order to vote for PR (so assuming they vote PR at 75%), then I have the YES side AHEAD by 1700 votes! Imagine winning this referendum with a 50.07% margin! Take that 1995 Quebec referendum!

My conclusion remains the same: it's incredibly close. Maybe our post-referendum poll will help us there (hopefully, maybe we'll see that young people chose the YES even more or that the undecided that were over 55 also rallied behind the YES).


Is the turnout still affected by when a riding received the ballots?

A regression-based analysis is required here. As a reminder, not every riding got their ballots at the same time. Elections BC is only providing the date at which it was supposed to all be received. However, I came up with my own measure because even among ridings scheduled on the same day, you can clearly see differences (possibly due to the rotating postal strikes). I use the numbers of days the ridings has been above the 1% turnout threshold.

Results are below:


So the answer is yes, the variable "number of days of voting" (measured as the number of days above 1%) is still significant. The coefficient hasn't changed much recently either. This could potentially be hugely problematic. Elections BC still has a lot of ballots to process and it's possible it'll even out at the end, but we are one day before the deadline and it hasn't yet. Coefficient of 0.03 means a turnout higher by 0.3% for every additional day of voting. And that's after controlling for the region and other factors.

I even ran robustness checks (with the help of Jameson Quinn, Ph.d student in statistics at Harvard) to make sure the effect was there. Specifically, I identified the ridings that were less "enthusiastic" or motivated to vote and used "number of days above 0.5%" for them. The idea being that my measure could have been biased since ridings that are less motivated would also reach the 1% mark later. Doing so changed nothing to my regression (in one version it decreased the coefficient from 0.03 to 0.027).

So in average, and after controlling for multiple factors, I still find that a riding that got its ballots 10 days sooner has a turnout about 3 points higher. This is potentially important because there are a large group of ridings (19 to be exact) that were scheduled for November 2nd and that only crossed the 1% mark 19 days ago while 17 ridings scheduled for Oct. 24-26 (mostly in the interior) crossed the 1% mark 32 days ago!

With that said, I also ran estimations of the impact of this turnout on the votes and found nothing. Specifically, I removed the effect of the number of days on the turnout (so I simulated the turnout of every riding if they all had the same number of days) and re-ran my estimates above. There was no change in method 2 and a tiny increase (of 0.04%) for the YES with method 1.

So while I'm fairly convinced the turnout was indeed affected by when a riding got their ballots, it seems that the overall impact on the YES and NO side is zero.