Purcell has research interests in the social, economic and cultural history of Rome and the City of Rome as well as the Mediterranean Sea and its history.[7]
Purcell is known especially for his 'ecological view' of ancient history as well as his expertise in ancient Mediterranean history.[5] The publication of his book The Corrupting Sea: A Study of Mediterranean History (co-written with Peregrine Horden) was hailed as a 'notable intellectual event'.[8] The book's main thesis is that the Mediterranean is a region made up of micro-regions.[8] The book argues that the Mediterranean ought to be seen in terms of the ecological lines of force linking countless small regions and micro-economies together rather than in terms of a few famous metropoleis.[5] Purcell stresses the longue durée and insists that the different themes of history, i.e. politics, culture, economy, ideas and institutions must be studied in close association. Purcell is currently concerned with expanding this work and with situating the Mediterranean in even larger contexts so as to show how ancient history can be used to answer global historical questions.[7]
Purcell, Nicholas (2003). "Becoming historical: the Roman case". In David Braund; Christopher Gill (eds.). Myth, History and Culture in Republican Rome: Studies in Honour of T.P. Wiseman. University of Exeter Press.
Purcell, Nicholas (2005), "Romans in the Roman world", in K. Galinsky (ed.), The Cambridge Companion to the Age of Augustus, Cambridge University Press
Purcell, Nicholas; Horden, Peregrine (2006). "The Mediterranean and "the New Thalassology"". The American Historical Review.
Purcell, Nicholas (2007), "The horti of Rome and the landscape of property", Res bene gestae: ricerche di storia urbana su Roma antica in onore di Eva Margareta Steinby
Purcell, Nicholas (2012), "'Romans, Play On!' Rome, city of the Games", The Blackwell Companion to the City of Rome, Blackwell