Innovative, radical international adviser on government policy, he had a lifelong association with the LSE
William Plowden, who has died suddenly of a stroke aged 75, was a founder member of the innovative Central Policy Review Staff (CPRS), set up by Edward Heath in 1971 to provide the cabinet with advice on strategy. William had a wide range of expertise and interests, in transport policy, social policy and government. His career developed from academic life at the London School of Economics (LSE) to advising on public policy in the civil service and then to international influence as a sought-after expert in government.
William's great contribution was to assert the need for social policy to be based on an understanding of the impact of policy, priorities and expenditure on people. The proposals in the 1975 CPRS report A Joint Framework for Social Policies were badly needed. It was greeted nervously by ministers, and by the Treasury. Social scientists still refer to it. William's blunt central thesis repays reading now: "Ministers need to ensure that their priorities are adequately reflected in policies which are actually being carried out and that, in practice, these policies are having the effects intended."
William's unforgettable characteristics were his charm and his courtesy, allied to a scholarly rigour in ideas and debate. His strong views, and he had many, would be discussed in a way that could persuade his hearers to accept the most radical propositions. Conversation with him would always improve an idea or the thread of an argument. After a session in his kitchen in Stockwell, south London, with the cat, the seedlings, the coffee pot and the camellia outside the back door, problems were smoothed out and a better way forward agreed.
William was born in London, the elder son of Sir Edwin (later Lord) and Lady (Bridget) Plowden, both steeped in the system of British public administration. William, too, was concerned with the effectiveness of government, but his views were unconventional. Although he was at school at Eton and university at King's College, Cambridge, it was time spent at the University of California at Berkeley as a Commonwealth Fund fellow that encouraged him to think radically about British life. He returned to London for a year on the Economist and five years at the Board of Trade. In 1965, he began a lifelong association with the LSE, moving to the Central Policy Review Staff in 1971, where some of his most influential work was done.
As his career took him from the LSE in the 1960s to the CPRS in the 70s, then to be director general at the Royal Institute for Public Administration (RIPA) in the 80s, William demonstrated his talent for making friends and maintaining links. He moved to New York as executive director of the British Harkness fellowships at the Commonwealth Fund, but returned to London in 1991 to develop a new role as an expert on cabinet government and public administration.
His determination that policy should be supported by accurate and relevant data was evident in the innovative use of charts and diagrams in many CPRS reports. He made a major contribution to the work done on central and local government relations and on the development of a range of influential reports on neglected social policy issues, including the needs of groups such as children and the elderly, at a time when Whitehall was firmly focused on organisations rather than people.
William's thinking retains its relevance. His first publication, The Motor Car and Politics in Britain, published in 1971, was described at a recent conference as still radical. The second chapter of the book he and Tessa Blackstone published in 1988 about the CPRS, Inside the Think Tank, is a masterly summing-up of the recurring problems at the centre of government.
William returned frequently to the theme of the British civil service. His experience as a young civil servant in the 1960s, in the CPRS and at RIPA, fuelled his view that radical changes were necessary if the civil service was to survive. He wrote, with two colleagues, a paper for the Fulton Commission in 1967, and returned to the subject in 1994 with his much quoted report for the Institute of Public Policy Research, Ministers and Mandarins.
From 1991, for 15 years, Plowden travelled the world advising worried and confused politicians grappling with the demands of modern government on how to organise the process of policy-making and decision-taking. He returned regularly to Peru, Mexico, Mozambique, Brazil and Russia, but became increasingly perturbed by the failure of the major aid donors to recognise the limitations of what they could do in support of better governance.
A three-year period of research, discussion and debate led to the writing of Governance and Nationbuilding, published in 2006, in which together we analysed what was happening in the governance of developing countries and the way in which aid resources achieved poor and often damaging outcomes. It was, in his words, "a system designed so that no one has an interest in telling the truth", although the truth was well known and unpalatable. He urged a modest set of objectives on the aid donors which would be more likely to achieve results.
The LSE provided a base for his writing and research. He was a visiting professor both in the 1980s and again from 2002, a governor from 1992 and a member of the council for several years.
William married Veronica Gascoigne in 1960. They lived in Stockwell from 1962 and shared a farmhouse in Gloucestershire with friends. Seven years ago, William bought a wood nearby which he and Veronica tended with delight. He was an expert on English watercolours and a talented painter. He travelled widely, was always up to date on films and concerts, and loved steam trains. One colleague remembers waiting with a baffled group of Chinese social scientists in Beijing while William insisted on climbing all over an exceedingly elderly engine, covered in soot. In London, he always travelled by bicycle.
Veronica, their two sons and two daughters, and seven grandchildren, survive him.
• William Julius Lowthian Plowden, policy adviser, born 7 February 1935; died 28 June 2010