Globally renowned universities are ranked by reputation

The World Reputation Rankings measure an increasingly vital element in the social-network age, say Phil Baty

Reputation is subjective, messy and nebulous, but it matters deeply in today's competitive global higher education sector.

Research has shown that a university's reputation is the top priority (over location or even salary) for academics moving jobs, and it is the number one consideration for internationally mobile students, above tuition fees and course content.

It can also be key to attracting collaborative partnerships and funding from alumni, philanthropists and industry.

And although reputations once gained can often be stubbornly enduring, things can change quickly in an information-rich, multimedia and socially networked age. The stakes are high.

"The strength of a university's brand both depends upon and feeds into the success of the institution itself," writes David Copping, a senior associate at the London law firm Farrer & Co.

"If a university thrives, the value of its brand will increase, in turn creating a virtuous feedback loop as academics, students and funding are drawn in. But the reverse is also true: failures of compliance or strategy can tarnish and at worst destroy this key asset, trapping the institution in a downward spiral."

Given the importance of what is at stake, the Times Higher Education World Reputation Rankings have quickly developed into a powerful and highly cited global benchmark of universities' academic prestige - a trusted brand index. So it is essential that the research underpinning the rankings can bear the weight being placed on it.

This top 100 list is based on the world's largest invitation-only survey of experienced, published academics, carried out by the polling company Ipsos MediaCT for our rankings data provider, Thomson Reuters.

Respondents are carefully selected to be statistically representative of their country and their specialist discipline, and are asked to name a small number of institutions based on their own expert, subject-specific experience and knowledge. So the list gives a representative and balanced view of the most prestigious academic institutions in the world.

The 2013 rankings are based on a staggering 16,639 survey responses. In the three short rounds of the annual survey thus far, almost 50,000 responses have been gathered from more than 150 countries.

The reputation rankings are based on nothing more than subjective judgement, but it is the judgement of experts. It is thanks to their expertise and engagement with this important exercise that we can bring you this trusted picture of the most reputable universities in the world.

Phil Baty is the Times Higher Education World University Rankings editor