An employee is working overseas for a U.S. employer, and the agreement was that the employee would receive a return ticket home at the conclusion of the contract. The employee wants to resign from the contract five months early. The employer says that the employee must complete the contract or pay for his own return ticket home.
Can the employer require the employee to buy his own return ticket? The work is in Asia and the ticket is quite expensive.
Would it make a difference if the employer already purchased the ticket, and is asking the employee to reimburse them for the cost?

