Ta-da!

Enthu
made a comment:

This was an even worse miss than the Brexit vote by GJO.
Wonder what's wrong with us when it comes to forecasting items that we want to come true!

dsarin
made a comment:

Same for the Hungary referendum: 95% for the turnout to be over 50%. (Not sure there was a want for it to come true)
In micro economics most of the predictions are wrong because the market participants are assumed to be rational and logical. It is so difficult to go against the consensus when all the 'experts on the ground write' "Colombians expected to say ‘yes’ to peace".
In the case of Brexit I learned that people in the capital lived in the different world from the rest of the UK.

Inactive-5001
made a comment:

90%+ forecast is absolutely called for when the polls are 66%+, *assuming* polls accurately reflect voters' intentions. The big problem is that sometimes they do (Peru), and sometimes they don't come even close (Colombia). I too totally blew Hungary question: was absolutely convinced in 95%+ vote for "no" AND similarly convinced that the hot-button topic will overcome voter apathy. Still have no idea why not. Some surely took it seriously, going to quite elaborate effort to show what they stand for: https://i.guim.co.uk/img/media/ff0932f38e9b5546a32093182078fbffb0671736/43_249_2903_1742/master/2903.jpg

tsm
made a comment:

I think predicting vote outcomes is like predicting stock markets; people somehow have incentives to misrepresent and hide their true intentions.

HW15
made a comment:

the margin here was so small I should have put more credence in my last minute nod to Hurricane Matthew. I heard two radio reports today mention how the largely pro-yes northern Colombia stayed home due to rain...haven't looked up the exit data. Brexit, Hungary..these don't have a weather swan to blame...

Inactive-5001
made a comment:

It's not about the margin, it's about polls being >16% off. My Colombian colleague (who, in all honesty, is not a type interested in politics) says that all polls are bad in Colombia because all pollsters are bought off. I sorta don't believe her but if it's true and there was a good evidence for it, it would be case of the question researched poorly.