With the votes counted and with ‘leave’ achieving a slender victory we can now reflect a little on our predictions.
Over the past few weeks all of our data sources have been favouring ‘Remain’, so why has our data been returning results outside a realistic margin of error?
Exit polls strongly point to age being a decisive factor in this referendum
The latest YouGov Poll reflects this below:
With older age groups traditionally more likely to cast their votes, this has most likely amplified ‘Leave’ opinion. This stark age divide seems particularly prominent within this referendum, something which pollsters, bookies and the financial markets have all underestimated.
While we have been pulling data in from a range of sources to help shape our predictions, social data in particular may have presented certain additional interpretative challenges. This has had the likely effect of a fundamental under-representation of this key demographic group heavily in favour of Brexit.
While we did adjust our models to compensate under normal circumstances, the measure of adjustment was clearly below that required to reach an accurate assessment on this particular referendum question.
Likely this large disparity based on age has also filtered through across main polling methods and other measurement systems.
A final word
Overall around 13% of voters were still undecided the day before polling, something which has had the deciding influence over the referendum result. Whether on or offline, if people are unwilling to share opinion or have yet to decide until the last minute based on gut instinct, it is difficult for any measurement to be truly reliable. We can only conclude that human nature remains as unpredictable as ever!
Luckily for us, our media channel planning skills based on rigorous forecasting are not dependent on a person writing a cross at the ballet box!
Other posts in this series
EU Referendum Week 1 - What does the data say?
EU Referendum Week 2 - Can hashtags provide insights?
EU Referendum Week 3 - When will the touch paper be lit?
EU Referendum Week 4 - Driving social followers
EU Referendum Week 5 - Will turnout be decisive?
EU Referendum Week 6 - Is social data underrepresenting female opinion?
EU Referendum Week 7 - Time for the undecided voters to make their decision