Education around the world could be completely redefined by the growth of a global middle class working for multinational companies, new research claims.
Stephen Ball, professor of sociology of education at the Institute of Education in London, believes that this globetrotting elite is bringing an element of internationalism to schools across the world. A significant proportion of expats have young families.
The traditional choice for these families is to send their children to boarding school in their country of origin. "But, with the increase in mobility, this isn't the case any more," says Professor Ball.
"More families want to take their children with them. They see value in their children having an international education." So they look for alternative forms of education. The second option is to send their children to local schools in their country of residence. This is common in developed cities, such as London, Paris or New York.
Other expats, however, have no interest in paying local taxes or using the local education system. Instead, they send their children to private international schools.
"These people have a post-nationalist sensitivity," says Professor Ball. "They no longer see sense in commitment to a particular country: they see themselves as globals or cosmopolitans."
Academics are divided on the impact of either local or international schooling on expat children.
"Some people suggest this leads to a sense of alienation," says Professor Ball. "There's a loss, a rootlessness, a lack of belonging. There's a sense of not being one thing or the other."
Others, however, believe that the advantages outweigh the disadvantages. "They talk about cosmopolitanism as a positive thing," Professor Ball says. "Children develop skills of language, tolerance and adaptability."
But the education choices made by this global middle class have had implications not only for their own children, but also for schools across the world.
Where expat children attend the local school, that school can take on a different character. For example, Wix Primary in south London has adapted to accommodate the needs of a large French expat community. In September 2006, it became the first bilingual state school in England, teaching lessons in English and French.
Equally, where expats choose to send their children to international schools, this creates a thriving market for elite private education. As a result, aspirational middle class locals decide to educate their children privately too.
This is particularly the case in countries such as China, Singapore and Korea, where a private English education is seen as an entry pass to the international job market.
To meet this growing demand, English public schools are increasingly opening offshoots overseas. For example, Dulwich College has opened several branches in China, and a branch of Haileybury opens in Kazakhstan this September.
But it is not just the private sector that sees this trend as a money- making opportunity. Many state schools, particularly in Australia, New Zealand and Canada, are trying to attract fee-paying foreign pupils, just as universities have done. For example, in the town of Squamish in British Columbia, a state secondary runs a stream for Korean pupils. They study the Canadian curriculum during the day and the Korean curriculum in the evening, and live in a nearby accommodation block.
Professor Ball believes this could be the beginning of a global trend.
"These children are preparing to enter the global workplace," he says. "They're learning to fit in. And they're becoming flexible and adaptable in new kinds of ways."
From Kent to China, teaching with a cosmopolitan touch
Wix Primary, Wandsworth, south London
Since 1993, Wix Primary has shared premises with L'Ecole de Wix, a primary school catering for the children of French expats in London.
In 2006, the two schools decided to create a joint bilingual stream. English and French pupils are now taught together, with teachers using an equal balance of both languages.
The Wix curriculum meets the needs of both the French and English education systems, so that pupils can continue their secondary education in either country.
Dulwich College, south London and China
In 2003, Dulwich College took its first step towards creating an international franchise by opening Dulwich College, Shanghai.
Catering for pupils from nursery through to secondary, it follows the English national curriculum, culminating in the IGCSE and international baccalaureate (IB).
Opened to serve the expat community, it also offers places to pupils who "regard (China) as their home". In 2005 and 2007, branches opened in Beijing and Suzhou.
Sevenoaks School, Kent
For 30 years, Sevenoaks has allowed pupils to take the IB instead of A- levels. For the last five years, this has been the sole qualification offered to sixth formers.
Situated within commuting distance from London, the school serves a large international community. Its sixth form attracts pupils from 35 countries. Pupils go on to universities in Britain, the US and Canada.
Fees are Pounds 5,312 a term for day pupils and Pounds 8,518 a term for boarders.
The American School in London, St John's Wood
Established in 1951, The American School in London educates more than 1,300 pupils between the ages of five and 18.
While it follows the US curriculum to prepare pupils for entry to universities there, its pupils are drawn from more than 50 countries.
Each year, around a fifth of the school is composed of new pupils who have just relocated to London. Others choose to transfer to the US system after several years in British schools. Fees are Pounds 20,000 a year.