repeated criticisms, the MBA remains a popular qualification for a career in business. Even though some well known gurus have joined the critical chorus, the supply of talented people wanting the qualification continues to grow. Does the international cadre of MBA students know something the mighty critics do not? I think they do.

An MBA offers three distinct advantages. First, it provides access to new knowledge. A good programme gives insight into the knowledge that has transformed many parts of the business world and provides an awareness of the shifting context of modern business. It also provides a basis for appreciating and developing the arts of management, very practice of the craft.

Second, an MBA from a good institution can provide access to a powerful network of contacts: its alumni, friends and supporters.

Third, an MBA from a respected and well-known school provides an entry point for the national and international managerial labour markets.

All three advantages are important in their own right. But access to knowledge about management itself is only a part of the significance of the MBA, although it almost monopolises the attention of some critics, particularly Henry Mintzberg, who says conventional MBA programmes ignore the art and practice of the managerial craft.*

However, the vast majority of MBAs will be entering careers where managing per se will not be an overwhelming part of their work for many years. This is so in consultancy, in many newer economic sectors where enterprises operate with flat hierarchies, and for the majority of those going into the financial sector.

While many critics minimise the advantages to be gained from an insight into newer managerial knowledge, they are wrong to do so. Modern managers need to understand the advances in finance theory, organisational design and information processing that have transformed businesses. In many sectors of the economy, such knowledge is no longer optional.

Not too long ago, much of this cutting edge learning was only available at a few institutions, almost all in the US. For modern finance it was necessary to go to Chicago, Wharton, Rochester, MIT or Stanford, places where the knowledge itself had been created. But the world of knowledge is a democratic one and the new teachings are now available at even the most humble of MBA schools.

But some of the other advantages of the MBA are not so evenly distributed. Only a few schools offer access to really significant multinational business networks, although a few more provide entry to powerful regional ones. Perhaps Harvard and Stanford reign supreme in the former, but Bocconi has no equal for opening doors in Italy, just as the top Spanish schools provide access to the Spanish speaking world.

The same applies to providing access to the top national and international managerial labour markets. This is a benefit that provided the impetus for the post-war expansion of business schools in the US. As business itself became a national rather than a regional phenomenon, so did the market for managerial talent. MBAs undoubtedly promote meritocratic advance and, in the process, change the social composition of business.

This has now become an international phenomenon. MBA programmes are powerful instruments in promoting geographic mobility that would be difficult to achieve by other means.

More than that, the degree has become associated with enabling other forms of mobility. Production managers can move into finance or consultancy to the enrichment of the both. Nowadays, it is the software engineer in the late 20s, seeking a way out of a career with limited opportunities and bringing the latest technical understanding, that can benefit business.

Equally, those who have already worked in consulting or investment banking can prepare to set up their own entrepreneurial ventures.

Not only are these transformations personally enabling, they also enrich the wider economic and business environment, shifting talent to new areas and creating people who can operate in diverse and interdisciplinary contexts.

Yet the critics of the MBA have largely ignored these important labour market roles. For instance, Stanford's Jeffrey Pfeffer, professor of organisational behaviour, makes a great deal of the finding that MBAs seemingly command no salary premium in the consultancy sector over non-MBAs. But he provides no information on the contrasting backgrounds of the two groups.

A top Ivy League or Oxbridge undergraduate degree can still get you into a leading consultancy firms, as does a record of distinguished service in a functional managerial role. But the consultant with the MBA who has worked her way up from humble origins at Nebraska State (or the University of Northumbria) would never be working in the New York office of McKinsey – or Goldman Sachs – without that additional qualification.

Of course, some of the concerns with MBAs are right. Even I was critical when a 20-something Stanford MBA working for McKinsey on a pro bono project at the University of Oxford asked how I would measure quantitatively the performance of the Sa?d Business School. Here was a person with an answer that was looking for a problem.

So there is room for improvement, but the MBA is nevertheless a powerful qualification in today's global business world. However, the prospective student needs to reflect carefully on the advantages it offers. For if the interest is largely posited on the networking and labour market benefits, it needs to be recognised that these are only available at a limited number of institutions.

While the knowledge offered by the MBA is much more widely available, the major recruiters only focus on a small number of schools thinly scattered around the world and perhaps even fewer schools offer really worthwhile networks of contacts. This is why MBA rankings have proved so influential. The Financial Times does a reasonably good job in identifying those schools that have clout in the non-knowledge arenas, which is why the London Business School can compete in the rankings with the Nobel Prize winning Chicago Business School. London is perhaps now more firmly established in the recruitment stakes even though it has never been a knowledge creator in the Chicago sense.

Even the guru critics may not really be convinced of their own arguments as most are established publishers of MBA textbooks, providing some of the knowledge on which the MBA enterprise continues to operate. If my reasoning is correct, it will continue to do so, to the advantage of the business community as a whole.

*Henry Mintzberg, Managers Not MBAs, 2004

Professor Anthony Hopwood stepped down as the dean of the Sa?d Business School, University of Oxford, in September 2006 to return to research and writing. He is also the Chairman of The Prince's Foundation for the Built Environment