Since it is the topic of the day, let's turn it into a statistical question.
Preliminary polls are showing 52 to 48 in favor of staying in the EU in terms of vote.
However bookies are giving a 80%+ chance for UK to stay in EU in their bet odds.
Clearly the bookie odds are linked to the uncertainty in the measurement. If we knew that the result will be 52 to 48 for sure then bookie would assign 100% chance.
Now how do we go from the preliminary poll results to bookie odds with some distributional assumptions, the number of people answered the exit poll (n) and the number of total voters (N), with the simplification that the people answered the poll honestly?