Part of the problem is that companies don't know how to manage their employees abroad. "Expatriates are among the most expensive people for an organisation. They are invariably in critical positions and yet are a difficult group of people to manage effectively," says Dr Hilary Harris of Cranfield University's newly founded Centre for Research into the Management of Expatriation (Creme).
The centre has been set up to explore best practice and to develop solutions for companies. "We are looking at every stage of the cycle from recruitment to how staff are managed when they return to the UK," says Dr Harris. She adds that few companies prepare employees for foreign assignments and many fail to deal with the issues associated with working in a cross- cultural environment. From the outset, the selection process is often haphazard. "We call it the coffee-machine syndrome. It's often very informal and a manager will just say: `Joe, how do you fancy Venezuela?' " says Dr Harris.
When an employee begins a foreign assignment, culture shock sets in. David Ellison, director of the Centre for International Briefing, an organisation that helps prepare expats for life abroad, says that even in the developed world, things are very different. "Most expats are now sent to the US and people often think that because it's English-speaking, there'll be no problems. But even in the US, business culture is different - on the surface they may appear relaxed, but in reality it is quite formal."
Dr Marx adds that there are many differences in the way that business is carried out in other countries. French businesses are hierarchical, while the Germans take a structured approach to everything, unlike companies in India and Brazil. "Managers who are best able to conquer culture shock are those who have a good understanding of these different business cultures, as well as cultural differences," she says.
Expats may face hostility from local managers. "If a company is truly global then why not use local staff rather than sending someone in?" asks Dr Harris. "It can cause a lot of resentment and tension. In the past, you were sent out somewhere and controlled everything; now interpersonal skills are important."
But perhaps the biggest problem for expats is the impact that a foreign assignment has on family life. "All the research shows that the main reason for the failure of foreign assignments is that family members do not settle in," says Mr Ellison.
The days of the dutiful wife following her husband to far-flung destinations and spending her time playing tennis and handing round canapes at cocktail parties, are long gone. "Organisations are struggling to cope with dual- career couples. It still tends to be women who give up their careers, but some men follow their partners. Companies can rarely offer both a job," says Dr Harris.
Mr Ellison says that foreign assignments tend to work best if a couple has a young family. "It is easier to meet people that way. But if you are on your own, stuck out in the suburbs of Chicago while your partner is at work, it can be very tough."
As well as the dual career issue, expats have health and safety to worry about. "Safety is an issue in all of Africa, most of Latin America and Russia and we try to prepare people before they go out there," says Mr Ellison, who has helped to prepare staff from companies such as Unilever, Boots and Blue Circle.
But perhaps the biggest culture shock of all is coming home. Mr Ellison says that it can be difficult readjusting to life in the UK, and some expats find that they do not even have a job to return to as companies contract.
Dr Marx has interviewed a number of returning expats and says that the following comments are typical: "When I came back to the UK, I felt alienated. I was unsettled for at least a year and felt I didn't fit in.
"I had problems coming back from Vietnam adjusting to the lifestyle in the UK. I felt that attitudes in Europe are so negative compared with the optimism in Vietnam. Our lifestyle has definitely downgraded." She adds: "Coming home is far from simple. Their own country, organisation, friends and family have changed - and so, probably, have they."
`Breaking Through Culture Shock' by Dr Elisabeth Marx is published by Nicolas Brealey, price pounds 18.Reuse content