Research Director for the IFS Tax Law Review Committee

Visiting Professorial Fellow, Queen Mary College, University of London

Visiting Professor of Tax Law, London Schoool of Economics and Political Science

Member and (since 1996) Vice-Chairman of the British Branch Committee of the International Fiscal Association

Member of the Permanent Scientific Committee of the International Fiscal Association

Member of the Taxation and Economic Committee of the Institute of Directors

Member of the Inland Revenue's Tax Law Rewrite Consultative Committee

Rapporteur to IFA Research Project 2 on source taxation of derivative financial instruments

Deputy Special Commissioner and part time VAT and duties Tribunal Chairman

Panel member under the EC Arbitration Convention

Senior Visiting Fellow, Queen Mary and Westfield College, University of London

Chairman of the Capital Taxes Group of the Institute for Fiscal Studies, set up to study the taxation of savings and profits

Chairman of an IFS committee to consider the reform of the basis of assessment for the self-employed

Member of the IFS Tax Law Review Committee

Lecturer on financial markets and insurance taxation on the OECD's programme for developing countries

Unilever Professor of International Business Law, University of Leiden, The Netherlands

Greenwoods & Freehills visiting professor of international tax law, Sydney University Law School, NSW, Australia

Chairman of task forces set up by the Centre for European Policy Studies, Brussels, to study the future development of tax policy in the European Union

Member and (1996-1997) Chairman of the Revenue Law Committee of the Law Society

Member of Council and (1993-1994) President of the Chartered Institute of Taxation

Member of Council and Secretary of the Association of Taxation Technicians

IFS Secretary (1985-1991); Chairman of the IFS Executive Committee (1991-1997); Member of Council (1985-2001)

Member of the Special Committee of Tax Law Consultative Bodies

Member of Taxation Committee of the London Chamber of Commerce and Industry; Chairman of Tax Committee and Member of LCCI Council (1989-1992)

Member of the Fiscal Studies Task Force on the Effect of the Tax Sysytem on Innovative activity for Cabinet Office's Advisory Committee on Science and Technology

Member of the Cabinet Office's Taxation Deregulation Working Group

Consultant to the Committee on Fiscal Affairs of the Organisation for Economic CO-operation and Development (OECD) on its report on The Taxation of Profits in a Global Economy

Consultant to Working Party 2 of the Committee on Fiscal Affairs of the OECD on the taxation of collective investment institutions