It's kind of a fact of life that we have to turn over every rock we can.

Marj Adler, personnel director, Pennsylvania schools

While in England schools have tended to recruit staff from Commonwealth countries, such as Australia, New Zealand and South Africa, in the US schools have recruited from a wide range of countries.

These have included regions such as Eastern Europe, South-East Asia, Central America and the Pacific Rim.

In Philadelphia school authorities are seeking to recruit teachers from Spain and India with science and maths teachers in particular demand.

Deprived areas

What will also be familiar from recruitment difficulties in England is that struggling schools, particularly those in more deprived areas, have greater problems finding staff.

Qualified teachers in the area often prefer to apply for jobs in the more affluent suburbs rather than in inner-city schools, which often suffer high levels of violence and low academic achievement.

Marj Adler, personnel director for Pennsylvania schools, said: "Someone who wants a job in math and science can make a lot more money in a lot easier role elsewhere.

"It's kind of a fact of life that we have to turn over every rock we can."

As a starting salary, teachers in Philadelphia can earn $31,000 (�21,500) which compares favourably with teachers' pay in India, Spain and the Philippines.

Among the cultural differences highlighted by Spanish teachers now working in Philadelphia is the greater need for security.

One teacher who made the move, Alberto Garcia, said: "Being a teacher here, you have to be an entertainer. In Europe it's more academic. People in Spain, they don't really know what it's like here, even when you try to tell them. We don't have metal detectors or police officers."