Professor O'Hara is primarily interested in British central governments' economic and social policies, focusing especially on the period since the First World War, and has written and edited a number of books on this subject. In 2012 he published another full-length monograph on this theme, entitled Governing Post-War Britain: The Paradoxes of Progress
(2012), and he has just published The Politics of Water in Post-War Britain
(2017). He writes regularly in the media on current affairs and policy. Professor O'Hara can be followed on Twitter as @gsoh31
, and between 2010 and 2020 he blogged in a personal capacity at the website 'Public Policy and the Past'