According to markets, Brexit has a 38% of occurring, in that there is a 38% of the United Kingdom (UK) leaving the European Union (EU), and 62% of staying in the EU. At the exact same time the HuffingtonPost Pollster trend is 45.6% for leaving the EU and 43.1% for staying in the EU. This follows a similar pattern to previous separatist votes in established democracies: polls leaning toward the separation happening, but markets correcting predicting it will not.

First, in both Scotland and Quebec’s separatist votes from the United Kingdom and Canada respectively, poll responses were inflated for the leaving the union. This is understandable in that within a given geographic area, there is general considerable social desirability bias in supporting separation. Everyone wants to sound like they are part of the crowd; they love their country and their people. The reasons for staying are generally more mundane and less sexy than the reasons for leaving. So, when someone calls with a deep Scottish or French Quebec accent and asks if you want to leave the union there is a lot of pressure to say yes! But, when the same people get into the voting booth they choose the less sexy, but more stable, answer.

Second, 45.6% + 43.1% = 88.7%. Undecided is trending at 11.3%. The undecided tend to break towards staying in these types of votes. If a voter is truly not certain, but votes, it is easier to vote for continuity than change.


Where Yes means stay in the EU …

These are two reasons to expect staying to over-perform the polling. But, as undecided poll respondents got off of the fence in the last few days, they have pushed the leave poll response upwards. Could this be different?

The demographics of this vote are opposite historical separatist votes. Normally separatists are generally younger and liberal. But, in this case the young overwhelmingly want to stay in the EU; it is older, conservative voters that want out. In the latest YouGov poll, 60% of 18-29 year olds want to stay versus 20% of them want to leave. In the same poll, 59% of 65+ and 55% of 50-64 year olds want to leave with just 30% and 33% respectively wanting to stay.

Polls are capturing a mix of sentiment and voter turnout. Traditionally older people are more consistent voters and this is something that the polling companies already control for. But, if the tight election draws extra voters that helps the stay vote; if it is a quiet election, UK will be leaving the EU.

Everything here about historical polling, demographics, and voter turnout is known to the markets. They have aggregated that all to say 62% that the UK votes to stay in the EU. But, this number is falling fast as poll after poll giving leaving a commanding lead. This is certainly something I will be following daily for the next few days.