The student vote could help the Greens keep their Brighton Pavilion seat at the general election next year and give Labour victory in Brighton Kemptown.
The report examines the potential effects of a change in law which has brought in individual electoral registration (IER).
Until this year one person in each property – nominally the head of the household – registered everyone at that address.
Now it is up to each individual to ensure that they are registered to vote.
Some people have expressed concerns that the change will mean that fewer students are on the electoral roll. There will be campaigns to persuade them to register.
Looking at the local situation, the Higher Education Policy Institute said: “Although many students who voted for the Green Party intend to support Labour at the 2015 general election, students could help the Green Party retain their one parliamentary seat of Brighton Pavilion.”
The report said: “Brighton Pavilion was narrowly won from Labour in 2010. On current national trend alone, both parties would make gains but the seat would again be tightly fought.
“However, given the big Green vote among students at the Euro elections nationally, the constituency’s student population seems likely to play a pivotal role in determining whether the seat stays Green.”
It also said: “If the Conservatives do make a recovery in the polls between now and the election, the six most marginal Conservative-Labour student constituencies might well fall to Labour because of the student vote even if Labour do not generally make gains from the Tories.”
Number five out of the six seats was Brighton Kemptown, where Simon Kirby won with a majority of 1,328 over Labour in 2010.
The HEPI report said that 15 per cent of voters in Mr Kirby’s marginal constituency were students.
The study was published on the same day as Brighton and Hove’s first annual revised electoral register for the year ahead since the law changed.
Brighton and Hove City Council said: “There is still time to register and be eligible to vote in the 2015 general election.
“Residents are urged to register as soon as possible to ensure they are added to the rolling register, which is held on a database and used to generate the poll cards for voters.
“The rolling register records can be updated until (Monday) 20 April 2015.
“Residents are advised to sign up as soon as possible to be sure of inclusion.”
Among the groups most affected by the new system are students and young people.
The council added: “If you are unsure as to whether you are registered, please contact Brighton and Hove City Council’s Electoral Services office on 01273 291999 or email firstname.lastname@example.org.”