The increased global emphasis on high-impact scientific and technological research is on display in this year’s QS World University Rankings, which are dominated by institutions specializing in the STEM disciplines (science, technology, engineering and mathematics).

Massachusetts Institute of Technology (MIT) cements its place at the top of the table, ranking first for the third consecutive year. And fellow STEM institution Imperial College London is the biggest climber in the top 10, leapfrogging Harvard, UCL and Oxford to rank second in the world, tied with University of Cambridge.

With budgets from both public and private institutions coming under strain as the global economy attempts to bounce back from the recession, many comprehensive institutions have increasingly struggled to balance research excellence with small class sizes and comprehensive internationalization. The rankings suggest that STEM-focused institutions such as MIT, Imperial and Caltech are currently perfecting this formula.

Harvard University was the undisputed number one in the early years of the QS World University Rankings, topping the table every year from 2004-2011. Yet its dominance has been on the wane in recent years, and this year it slips to 4th. Local rival MIT retains the global top spot and in doing so underlines its status as the current number one university in Cambridge, Massachusetts.

MIT and Harvard both record maximum scores for academic and employer reputation, as well as research citations. The factors that tip the balance in MIT’s favor are its superior student-to-faculty ratio and more internationally diverse student and faculty makeup.

The basis for Imperial College’s eye-catching rise from fifth to second is its all-round consistency across the range of indicators. Imperial is the only institution that ranks within the global top 50 in each of the six measured criteria. This is testament to its success in marrying a strong research profile and international reputation with an excellent student-to-faculty ratio and highly international character.

US institution Caltech moves up two places to 8th, and is the world’s top university for research citations. Switzerland’s ETH Zurich (12th) and EPFL Lausanne (17) both feature prominently, meaning specialist STEM institutions now account for a quarter of the world’s top 20 universities.

Other STEM-focused institutions that have improved their performance this year include France’s Ecole Polytechnique ParisTech, up 6 places to 35th, Singapore’s Nanyang Technological University (NTU), which achieves its highest ever ranking of 39th, and Korea’s KAIST, which is up 9 places to 51st. KAIST’s improvement comes after it ranked 2nd in this year’s QS University Rankings: Asia, and continues an upward trajectory that has seen it rise from outside of the top 100 in 2007 to its present position on the cusp of the global top 50.

“In the wake of the recession, both governments and private sector funding sources have been putting a greater emphasis on high-impact STEM research, much of which takes place in specialist institutions such as MIT, Imperial College and Caltech,” says QS head of research Ben Sowter. “Tech-focused institutions are increasingly the focal point of a global race for innovation.”

However, while STEM institutions have prospered, several comprehensive institutions are finding it more difficult to keep pace. In addition to Harvard, Yale has dropped to 10th, the lowest ever ranking for an institution that was 2nd in 2008. University of Chicago has dropped out of the top 10 this year for the first time since the rankings were compiled.

As in recent years, the rankings also point to the shrinking number of affordable world-class institutions. State-funded comprehensive institutions have generally seen a drop off in their performance, with the exception of those in the UK, where as of 2012 the funding burden has been shifted substantially towards contributions made by students in the form of £9,000 annual tuition fees.

In the US, the highest-ranked public institution is University of Michigan, at 23rd globally and 12th nationally. UC Berkeley drops to 27th, and along with UCLA (37th) and University of Wisconsin-Madison (41st) there are just four US public universities in the top 50 – this compares to 14 private institutions.

A total of 31 countries are represented in the QS global top 200 printed here (the full list of 800 ranked institutions can be viewed at www.topuniversities.com). As usual, the US is the dominant nation, with 51 institutions, ahead of the UK (29), Germany (13), the Netherlands (11), Canada (10), Japan (10) and Australia (8).

The highest profile omission is India, which still has no institution in the global top 200. France has just four institutions in the top 200, placing it behind not only Germany and the Netherlands, but also smaller Eurozone neighbors Switzerland, (7), Belgium (5) and Sweden (5). Nonetheless, France’s top two institutions have both improved their performance this year, with Ecole Normale Superieure Paris moving up four places to 24th, ahead of Ecole Polytechnique Paristech at 35th=.

National University of Singapore (22nd) has cemented its current position as Asia’s top institution, opening up a six-place lead over University of Hong Kong (28th), which it overtook for the first time last year. Hong Kong’s universities have all dropped slightly this year, though this is likely to be temporary. All of the nation’s institutions have seen a drop in their scores for student-to-faculty ratio as a result of the ‘double cohort’ of students admitted in 2012 as a result of the switch from a three to four-year undergraduate degree model.

Like many Japanese institutions, University of Tokyo has seen its position drop over the course of the last few years, but this year it moves up a place to 31st=. However this is not enough to prevent it from being caught for the first time by Korea’s Seoul National University (SNU), which has been on the opposite trajectory. All of South Korea’s leading institutions continue their rapid ascent this year. SNU (31st), KAIST (51st) and Postech (86th) all achieve their highest ever positions, with the latter gaining 21 places this year.

Six of China’s seven top-200 institutions improve their performance, the exception being Peking University, which drops 11 places to 57th. Having closed the gap to just two places in 2013/14, Tsinghua University now replaces Peking as the nation’s number one institution, moving up one place to 47th. This fits in with a consistent pattern that has seen the majority of Chinese institutions improve their performance on a year-by-year basis, but with its top institutions failing to emulate the likes of NUS, University of Hong Kong, University of Tokyo and SNU by breaking into the global top 40.

The two major identifiable weaknesses here are research citations and internationalization. Despite all of the investments in research productivity seen over the past decade, Tsinghua and Peking rank 287th and 285th respectively for citations, and neither institution makes the top 300 for their proportion of international students. Whereas universities in Singapore and Hong Kong in particular are now globally engaged, international centers of excellence, Chinese universities’ comparative isolation has thus far prevented them from making the breakthrough into the upper echelon of elite global institutions.

After a couple of years in which Australian institutions have been feeling the effects of increased international competition, their performance has largely stabilized this year. University of Adelaide’s four-place gain means that for the first time since 2011 the nation’s elite Group of Eight institutions all feature in the global top 100 – a performance bettered by only the US and UK. Australia National University is up two places to 25th, pulling away from University of Melbourne, which drops two places to 33rd. However, outside of the Group of Eight no other Australian institution makes the top 200, suggesting that the gap between the best and the rest may be continuing to grow.

Canada’s top institution, University of Toronto drops three places to 20th, but still retains a slender lead over McGill University, which is one place behind in 21st, the same position it occupied last year. Behind the top two, the remaining eight Canadian institutions in the top 200 all improve their performance, with University of British Columbia moving up five places to 44th, and University of Montreal (83rd) and University of Alberta (84th) also in the top 100.

Latin America repeats its 2013/14 total of four institutions in the global top 200, with one apiece from Brazil, Chile, Mexico and Argentina: Universidade de São Paulo (132), Pontificia Universidad Católica de Chile (167), Universidad Nacional Autónoma de México (175) and Universidad de Buenos Aires (198). The sole African representative is University of Cape Town (141), with no universities from the Middle East making the top 200, though there are three institutions from Israel.