''The quickest way to immortality is to gift a collection.''
The quote, by American rare book collector Henry Huntington, is one of Dr Kerr's favourites.
He says collecting is grounded in human nature.
''There is the chase, the hunt for that one manuscript or book, and there is also the notion of completeness - getting everything that was produced by a particular person or company,'' Dr Kerr says.
''Collecting also has that physical, tangible nature to it. Perhaps it is all about possessions and feeling comfortable surrounded by things you really enjoy.''
He says the collector sees value in things, attaching significance to items as part of a whole.
Collectors must also have perseverance.
Some collect discreetly, in private, while others proudly display their treasures for all to see.
Collecting can be a very personal expression of oneself and there is inevitably the question of what to do with a collection once the collector has died, Dr Kerr says.
''Do you disperse it, push it back into the market place for other collectors, or do you try and find an institution to take it as a collection and make it available to the public?''He says ultimately a collection is the legacy a person leaves behind.
Dr Kerr has been the University of Otago's Special Collections librarian for the past 10 years.
He is fascinated by private book collectors, particularly those who have established New Zealand's foremost collections of published material including Alexander Turnbull, Dr Thomas Hocken and Sir George Grey.
''They are the trinity of book collectors in New Zealand.''
Mr Turnbull, a merchant, presented his Maori and Pacific artefacts to the Dominion Museum (now Te Papa) shortly before his death in 1918, when his book collection became the nucleus of the Alexander Turnbull Collection now housed in the National Library of New Zealand at Wellington.
Dr Hocken was a surgeon, coroner, collector, bibliographer and researcher.
In 1910, a few months before his death, he offered his historical collection of publications to Dunedin citizens and it became the Hocken Library, originally housed within the Otago Museum and still administered by the University of Otago.
Dr Hocken, who was the vice-chancellor of the university at the time of his death, also gave the museum his extensive collection of Maori cultural artefacts.
Sir George was a soldier, explorer and writer, twice governor of New Zealand and the 11th premier of New Zealand.
In 1887 he gave Auckland citizens a range of precious heritage material, today known as the Grey Collection, which forms a significant part of the Sir George Grey Special Collections: Ta Hori Kerei - Nga kohinga taonga whakahirahira at Auckland City Libraries.
Dr Kerr wrote a book about Sir George while working with the Grey Collection and has now finished his second publication - a book about Dr Hocken as a collector.
''With both, I forensically examined every book and manuscript that they owned. Working as a rare-books librarian, I find it interesting to see or learn how a particular book has arrived in New Zealand.
''The great thing about these three men is the fact they had their own private collections but then gave them to us and they became part of the public good - I think that's pretty neat.''
Dr Kerr is working on his third book in which he focuses on 12 New Zealand book collectors as well as collecting in a more general sense.
He wants people to remember that without the determined collecting efforts and generosity of the 12 men, including Alfred Reed, Henry Shaw and Robert McNab, New Zealand would be ''much poorer''.
''No-one had ever done any work on them as collectors, to look at why and how they got their collections together. Ideally, if you've got a whole lot of people doing work on all the main book collectors up and down the country, say 30-plus, at the end you could have quite a large body of knowledge about that collecting process.''
Working at institutions dedicated to collections brought out the ''collector bug'' in Dr Kerr, who is developing his own book collection.
He takes some inspiration from Dr Hocken, who he says was an excellent collector.
''In every letter going out from his house on Moray Pl he would ask people if they had any historical papers they wanted to assign to the waste bin and he would offer to take them. He did annual trips up and down the country and each time he reconnected with fellow collectors and offered to look after materials.''
Dr Kerr says some people are just born collectors, and the world is a richer place for it.