Informal Sector, also known as informal economy, shadow economy or underground activities, etc. has been recognized as an essential issue, which impacts economic growth and the responding policies. According to the World Bank (2016) research, the informal sector comprises at least 4 to 6% of total GDP in developed countries and more than 50% in those low developing countries (LDCs). Such as Laos, Viet Nam, Myanmar and Cambodia, it can be found that most of economic results are from informal activities and create major income for the locals. Besides, many informality-related issues in our society have gotten increasing attention, for example, the decent employment, human rights, fair competitiveness, poverty, lack of economic efficiency, etc. Many economists and policymakers believe that informal sector seems to play a negative role in economic growth and hamper our social development. Therefore, governments among vary countries tend to either reduce those underground activities or formalize them into regulatory framework.