It is important to ask questions about your current expatriate pay philosophy. Does your current expatriate pay philosophy drive the desired behaviour? Is the current policy and practice aligned to organisational objectives? Does the current policy work for or against the organisation achieving its global objectives?

We recommend a regular review of organisational expatriate pay philosophy in light of what the organisation seeks to achieve and where it operates geographically, whilst ensuring integration with the other pay related strategies of the organisation.
http://www.xpatulator.com/cost-of-living-article/Expatriate-Pay-Philosophy-_18.cfm