The PwC Modern Mobility report is based on a survey of about 200 global executives.
It suggests 90% of companies are planning to increase the number of employees working overseas across the next two years. However, only 9% are measuring the return on investment increased mobility brings.
Only three-in-10 companies know how many staff they have working overseas, while only 6% believe their mobility policies match the needs of their business. Additionally, only 8% are able to accurately measure the cost of their mobility programmes.
The report predicts that the nature of global assignments is due to change by 2020. The global executives polled expect short-term assignments to rise by 58% over this period. The use of people travelling more from domestic bases and talent swaps are also expected to increase.
Clare Hughes, a director in PwC's global mobility team, said the predicted increase in global mobility is "not surprising" given the needs of modern business.
"It is a great way for businesses to fill skills gaps, enter high-growth markets, attract employees and develop their people," she said. "For some companies, international experience is now a must-have for anyone taking on a leadership position."
But she warned that organisations' failure to track the costs of their mobility programmes will "cost them dearly" if it goes unchecked.
"Many businesses risk wasting considerable amounts sending the wrong people to the wrong places, overpaying for expats when local talent is available in-country or offering large financial packages when people are more motivated by the development opportunity," she added.
"Many businesses are also losing valuable talent at the end of the assignment, as they have no plan for their returning role."
