Beagle,
because the SNP took the view that impressionable, gullable, full of piss and wind 16/17yo's would be more likely to vote 'yes' than 'no'. the pollsters tell us that actually thats not true, or wasn't the last time i looked, and that are as broadly split as any other group with a slight majority as 'no'.
there was some guff about extending the vote to those who would be most effected by the result, but not only does no one believe it, the logic of that argument extends to giving the vote to four year olds, and oddly enough the SNP didn't push for that...
i'm still betting on a 'yes' with a tiny majority - firstly 'yes' people tend to be more passionate about their cause and are therefore more likely to go out and vote on the day than 'no' voters, and secondly because the 4 years of polling has said 'no' will win, leading, imv, to a certain complacency on the part of 'no' voters about the size of the 'no' vote - a proportion of 'no' voters will probably take the veiw that the referendum will be defeated without their vote. if enough people think that...
thirdly theres the 'don't knows' - the polls put the DK's at around 8-12% of the electorate who plan to vote. what they decide, and if they'll vote, will decide this - and i take the view that a majority of those who eventually make a decision and who then go out and vote will vote 'yes'.
i'm a 'no' by the way...