Stephen's main research interests are in innovation, enterprise growth and development, regional development, and industrial policy evaluation. Previous projects have been supported by the Economic and Social Research Council, the EU, the British Academy, and the Royal Irish Academy as well as a number of government departments in the UK, Ireland, US and Israel.

Stephen has consulted on aspects of innovation and enterprise policy for a wide range of organizations including the OECD, the DTI, the Department for Business, Enterprise & Regulatory Reform, the UK government's Small Business Service, East Midlands Development Agency, Advantage West Midlands, the Scottish Executive, Invest Northern Ireland, Forfas (Dublin), Enterprise Ireland, Northern Bank, InterTradeIreland, the Department of Enterprise Trade and Investment (Belfast), and the Department of Education and Learning (Belfast).