The study, by researchers from Edinburgh and Stirling universities, found large numbers of people saw risks both from Scotland becoming independent or remaining part of the UK.
However, it concluded they attached "greater weight" to risks associated with independence, such as losing the pound, than threats from staying in the UK, such as a cut to Scotland's budget.
The findings, which will be presented at Holyrood's annual Festival of Politics today, came as both sides in the referendum battle prepared to enter the final month of campaigning next week.
First Minister Alex Salmond will attempt to draw a line under days of pressure over his currency plans by staging a series of Scottish Government events in Arbroath on Monday, while Scottish Labour yesterday launched a campaign to win over undecided voters.
The new study, Risk and Attitudes to Constitutional Change, is part of the Economic and Social Research Council's long-running Future of the UK and Scotland programme.
The findings were based on a special ICM poll of more than 2,000 voters conducted in June.
Overall it found 70 per cent of voters (59 per cent of Yes supporters and 77 per cent of No supporters) believed neither campaign could accurately predict "the true consequences" of independence.
More than half (56 per cent) said it was impossible to be sure whether an independent Scotland could join the EU.
Asked about "risks of independence," 47 per cent said it was "totally unlikely" the UK Government would allow Scotland to keep the pound, compared with 38 per cent who believed it was "totally likely".
On the dangers of staying in the UK, 45 per cent felt cuts to Scotland's budget were "totally likely" compared with 36 per cent who felt it was "totally unlikely".
The study concluded the biggest influence on voting intentions was certainty on the issues, rather than feelings of national identity or trust in key figures.
It said: "If you are certain of the consequences of independence you are more likely to vote Yes.
"(These) results suggest that the referendum will be won or lost on the extent to which the two sides can reduce perceptions of uncertainty and convince opponents that particular anticipated risks are unlikely to occur."
The poll, conducted before the campaign burst into life after the Commonwealth Games, put support for No on 51 per cent, Yes on 38 per cent, with the rest undecided when people were asked the ballot paper question.
When they were asked simply which way they were leaning, 47 per cent backed No, 42 per cent Yes, with five per cent saying 50/50 and the rest unclear.
Better Together campaign director Blair McDougall said: "This study confirms that it is the economic arguments that matter and that it is our campaign that is winning the economic arguments. It confirms that losing the pound is losing the Yes campaign votes."
Yes Scotland chief executive Blair Jenkins said: "This research shows that the gap between Yes and No falls to just five points when people are asked for the probability of how they will vote, which indicates that opinion remains extremely fluid, with everything to play for on September 18."