SIR – We would like to challenge many of the assertions and “research” presented as evidence in your argument that “doing a PhD is often a waste of time” (“The disposable academic”, December 18th). Although some poor practices still exist, monitoring and mentoring systems have swept away much of the abuse that did undoubtedly occur in the past. Most institutions now monitor submission times, career destinations and earnings. The lack of permanent contracts is a trend throughout the professional world, not just in academia.

The PhD at research-intensive universities is a strong foundation for developing and managing the information society. Society needs highly trained critical thinkers to tackle complex problems with rigour and research skills. PhD graduates seek employment in academia, but also in research in the public, voluntary or private sectors and in a range of non-research jobs where they must analyse large amounts of evidence for complex decision-making. In Britain, less than 50% of researchers become academics. Hence there is no point in using manpower planning in the academic sector as the sole guide for PhD recruitment.

Moreover, it has long been known that there is no premium for undertaking a PhD. Few undertake a doctoral programme for monetary gain.

David Bogle

Professor

University College London

On behalf of the steering group of the League of European Research Universities Doctoral Studies Community

SIR – Discouraging the pursuit of the PhD degree would have serious adverse impacts on our ability to advance as a society—economically, technologically and culturally. Indeed, your own newspaper regularly touts the importance of scientific and technological advances in medicine, agriculture, energy and more. Our higher-education system of “apprentices” working with faculty is an important factor behind these advances.

Barbara Knuth

Dean of the Graduate School

Cornell University

Ithaca, New York

SIR – Who better to comment on the uselessness of doctoral degrees than an American pursing a PhD in Canadian studies? Many articles are written suggesting that graduate school is a waste of time; there are web comics (such as Piled Higher and Deeper) devoted to the difficulties that doctoral candidates encounter with their advisers; and there are people who are stuck in an endless loop of proposals, grants, unsuccessful experiments, etc. But I love what I do. I have the opportunity to teach and lecture. My adviser is supportive. I can spend all day thinking and reading books, and that is OK as it is my job.

A doctoral degree is a choice, just like any other career path. There are other people who have bad bosses and boring dead-end jobs with no clear means of escape. It might be more useful to direct advice towards those people, who are limited or constrained in some way, rather than doctoral candidates who can leave their programmes and do something else if they are dissatisfied with the process.

Amanda Murphy

Chicago

SIR – Scholarly learning or academic training is useless without either market demand or real-life applicability. The self-willed existence of redundant PhD programmes mirrors academic isolationism, anachronism and narcissism. It's time the academic world rethought the sustainability of the PhD system and reformed it in the best interest of both the gowns and the towns.

Daan Pan

Chino Hills, California

SIR – I am reminded of my very wise professor's words of wisdom: the PhD student is someone who forgoes current income in order to forgo future income. Years later, that sage insight seems to have been borne out by the more recent evidence.

Paul Greenberg

Managing principal

Analysis Group

Boston

SIR – The subtitle to your article on ships as polluters read: “Ships are filthy. A new website shows how filthy” (“Smokestack lightening”, December 11th). Shipping transports about 90% of the world's trade and emits 2.7% of the world's emissions. The per tonne of cargo transported by a very large crude-oil carrier of about 310,000 tonnes capacity is 153 times more energy efficient per tonne of cargo than a Boeing 747-400, 63 times more energy efficient than a small truck, 14 times more energy efficient than a large truck and five times more energy efficient than a train. This simple fact should have caused you to question the information on which you based your article.

Shipowners or operators have every incentive to economise on fuel consumption, considering fuel represents a very large proportion of the overall transport cost, but they do not design the ships. Every ship on the market wanting to secure employment is advertised with its deadweight capacity, speed and consumption clearly stated for all to see. Transparency in shipping is not an issue.

George Gratsos

President

Hellenic Chamber of Shipping

Piraeus, Greece

SIR – Thanks largely to technological developments and industry practice the energy efficiency of ships is some 20% higher than in the 1970s, which means ships burn less fuel and generate less emissions. To further reduce greenhouse-gas emissions from ships, the International Maritime Organisation's marine environment protection committee has developed a robust package of ship design and operation measures that are ready to be enacted as international maritime law. These could achieve reductions of up to 75% in ships' emissions and would be the first regulatory package adopted by any industrial sector at the global level.

Jo Espinoza-Ferrey

Head, policy and planning unit

International Maritime Organisation

London

* SIR – Regarding your obituary of Richard Holbrooke (December 18th), in 1996 I was treated to the full range of Holbrooke personalities from “bulldozer” to “charmer” all within four hours, spent mostly in a windowless government conference room in New York. As the Republican chief counsel for a congressional investigation, I was locked in an agonising debate with Mr Holbrooke, who was still basking in the glow of his Dayton triumph, during his deposition regarding Iranian arms shipments to Bosnian Muslims during the war. Assertive, contentious and fiercely protective of the Clinton administration's policy in the Balkans, he was nonetheless the most straightforward, honest and impressive witness I interviewed during the whole inquiry.

Minutes later he turned on the Holbrooke “charm”, chatting with me on the street beside his limousine from First Boston about the “obscene” (his words) amount of money he was being paid after leaving government. He graciously offered me a ride to the airport.

I left the experience dazzled against my Republican will, by a man I was certain would one day become secretary of state. Had Hillary Clinton been our president, I am sure he would have been and the “grand hooded phantom” yesterday's nightmare.

Richard Pocker

Las Vegas

SIR – Most of us regret the demise of so many British pubs, but in an otherwise excellent article on the subject you took an unnecessary side swipe at churches, which you described as “the preserve of a flower arranging few” (“Time, gentlemen”, December 18th). In fact, a survey in 2003 found that nearly nine in ten adults in Britain had been into a church the previous year. They can't all be flower arrangers.

Churches remain the hub of communities up and down our land, in the way that they were long before the appearance of the pub as we know it. The number of Church of England churches offering service to their communities exceeds the number of banks and building societies combined. The role of the church as the only remaining community facility in many rural areas is crucial.

John Inge

Bishop of Worcester

* SIR – Boozers are for losers, almost exclusively male losers, and the community of “regulars” of which they are the beating heart is in fact a marginalised clutch of the most boring, lonely and embittered outcasts one can imagine.

Unfailingly glued to the bar like flies to a flypaper, they greet a stranger with menacing silence while the landlord sullenly ignores him for as long as possible. The beer he eventually serves is a foul, brownish liquid, overpriced and sour-tasting. Conversation, when it resumes, is a bleak and xenophobic digest of the day's press opinion or, worse, a third-hand dismal exchange on what is laughably known as “sport”.

To anyone with a sane regard for social progress, the traditional pub cannot fail fast enough. It is encouraging that people are finally turning their backs on them. But hardly a mystery.

Rod Tipple

Cambridge, Cambridgeshire

SIR – Around 40 years ago some friends and I wandered into a small pub in Birstall, West Yorkshire. After enjoying the local bitter, we made the mistake of asking the elderly landlady whether we could have some crisps. She looked at us askance and tersely replied, “This is a pub, not a bloody restaurant.” Those were the days.

Bill Catley

Hong Kong

* Letter appears online only