Worldwide. the demand for skilled teachers is large and growing. A recent study by the American Association for Employment in Education reported teacher shortage in more than half of the fields surveyed. The United States is not alone: UNESCO reports that the market for pre-primary, primary and secondary education worldwide expanded by more than 142 million students between 1999 and 2006. This growth in students has resulted in a demand for an additional 7.7 million trained teachers.