Nonetheless, already limited budgets are strained by other demands and therefore do not extend to provide for this allocation or the meeting of these targets. The role which the private sector should play in such commercial development is not well defined, either. This can be partially explained by the household registration system (Ho Khau) which was put in place in 1964 (Work Bank and Vietnam Academy of Social Sciences, 2016) (Box 2.12). A technical problem is that migrants who are registered as short-term (seasonal or temporary) or returning migrants in the system are left out of urban statistics.