Migration has been occurring in the GMS for centuries, largely in an informal and unregulated fashion. In recent years, however, cross-border labor migration within the sub-region has increased sharply. The combination of demographic transition and upgrading of the skills of its workforce has left Thailand facing a labor shortage of unskilled labor, which migrants from neighboring countries have been more than willing to fill. Indeed, Thailand’s much higher incomes, fast growth, and more favorable social and political climate act as a magnet for people in Cambodia, Lao PDR, and Myanmar trying to escape poverty.