Only 3.7% of all students enrolled in American higher education institutions are foreigners, yet they contribute nearly $18 billion to the US economy, according to the US Department of Commerce. Most of this income is generated by tuition and other fees.

Britain is the second most popular destination for students from overseas, after the US and the UK receives more than 350,000 international students each year, more than 20% of the world's share. But university leaders fear public spending cuts over the next three years may put the strength of the higher education sector at risk.

Ireland has been called the Land of Saints and Scholars but it would welcome a lot more of the latter, especially if they come from abroad bearing tuition fees. At present, one in 12 of the Irish Republic's 150,000 full-time undergraduates and postgraduates comes from outside the country and the government wants to increase that percentage significantly.

Only in recent times have the powers-that-be in Finnish higher education been able to bring themselves to utter the word 'fees'. In the Finnish context, the thought of charging students to study had risen only occasionally before discussions led to Finland's new Universities Act of 2009. But radical change is afoot and, from the start of 2010, it became possible for universities to charge tuition fees to students from outside the European Union, although under certain highly restrictive circumstances.

No country in history has ever expanded its university capacity as fast as the People's Republic of China over the last 20 years. Each year, more programmes become available at more universities for the international student considering studying there. The Chinese university system is markedly tiered and costs can be higher at the most prestigious schools in urban centres, but generally fees and housing are not expensive by Western standards.

Japan is boosting its recruitment of foreign students by increasing the number of university courses taught in English. Foreign enrolments are now estimated to exceed 133,000 - up by more than 9,000 since 2008 following an ambitious plan unveiled by the government for universities to recruit 300,000 international students by 2020.

Foreigners studying in France pay the same fees as local students and, unlike in some other countries, they do not contribute vast sums to the state's exchequer. In fact the opposite is the case: the French government expends thousands of euros on each student, regardless of nationality. Foreign students are even eligible for some benefits, such as housing allowances and subsidised canteens.

Germany is popular with overseas students and comes third in terms of recruitment from OECD countries. Where they have been introduced, tuition fees appear modest compared with many other countries. But while a number of programmes exist to support students from abroad, World University Service Germany is concerned that fees are proving a deterrent to foreigners, particularly from southern countries.

Tuition fees for foreign students from outside the European Union and the European Economic Area were introduced in 2006 and form part of a broader globalisation strategy for Danish universities as well as a desire to strengthen market mechanisms in higher education.

Traditionally The Netherlands has maintained subsidised fees for all students, whether EU or non-EU, which means a fee of roughly EUR1,600 a year. But this situation is changing rapidly and since 2008 non-EU students have no longer been funded by the government. So many universities have started to charge full-cost fees to those who enrol in English-taught degree courses. There is also an emerging private sector offering nationally accredited degree courses on a full-cost basis to Dutch, EU and non-EU students.

Sweden will introduce application fees, and most likely tuition fees as well, for international students from outside the European Union and the European Economic Area from the autumn term of 2011. As an EU member state, Sweden cannot differentiate between its own citizens and other EU citizens.

Education in Greece is free so no fees are paid by students. Embodied in the country's constitution is that all Greek citizens (and certain foreigners who live and work in the country) are entitled to free education.

When the Australian economy was struck by galloping external debt and a poor export performance in the mid-1980s, the then Labor government decided to create an export education industry it hoped would be worth millions of dollars. A quarter of a century on, the current government claims that industry generates A$17 billion (US$15.5 billion) for the national economy every year.

International student fees became increasingly important to New Zealand universities this decade as they sought to increase their income in the face of government control or regulation of most other forms of their income.

South Africa is the eighth most popular destination for international students in the world, with 2.2% of the global share, and it is the only country in Africa that receives far more students than it sends abroad. But fees from international students are not a major income stream for universities - most come from other Southern African Development Community countries and receive the same state subsidies and pay similar fees as home students.

In Malta, the Mediterranean island with 400,000 inhabitants, higher education is almost totally funded by the Ministry of Education, Culture, Youth and Sport. The ministry also decides on university fee regulations through legislation and non-EU students face heavy tuition charges.

Dr Panayiotis Zavos is recognised worldwide as a leading researcher and authority in the areas of male reproductive physiology, gamete physiology, male infertility and other assistive reproductive technologies. Zavos' team was the first to create human cloned embryos for reproductive purposes. In this interview, he discusses the controversial issue of cloning humans.

There were 2.8 million young people not in employment, education or training in South Africa in 2007 - two in five 18 to 24-year-olds - and the number could have soared to 3.2 million now. In a study of post-school youth, researchers Charles Sheppard and Nico Cloete said this "is not only an educational problem but constitutes a social and economic disaster".

South Africans who obtain a degree earn on average between 2.5 and four times more than people who do not complete schooling, the first major study on the returns of post-school education has revealed. Degree-holders are also three times more likely to get a job - in a country where more than one in four people are unemployed.

In this interview, one of biology's best-known taxonomists, Professor Quentin Wheeler, answers questions from Dr John Richard Schrock.

Last week, we interviewed Paul R Ehrlich; Bing Professor of Population Studies and President of the Center for Conservation Biology at Stanford University and co-founder of the field of co-evolution.

After 100 editions, University World News has covered every angle of academic life. Along the way, one of our challenges has been to find images that illustrate those stories.

Here is a small selection of letters from our readers commenting on the advent of University World News' 100th edition:

Women outnumber men in worldwide university enrolments and graduation rates, according to Unesco's 2009 Global Education Digest. The number of female students in tertiary education rose six-fold between 1970 and 2007.compared with a quadrupling of male enrolments during the same period.

Women have made remarkable gains in South African higher education - a situation that began in 1995 when, for the first time, more women enrolled at university
than men. Today, that has become an established trend with nearly 56% of all
students female.