Tax is the main revenue of Government, so fighting tax evasion and sustainable growth have been the primary macroeconomic goals being pursued by every developing country, Vietnam included. The existence and development of the shadow economic sector are synonymous with the national budget losing out. In Vietnam, foreign direct investment projects do not promote economic growth and is also a sector that gives way to tax evasion.The purpose of this study is to investigate the impact of foreign direct investment, the quality of the informal institution on the size of the shadow economy in Vietnam, during the period 1991-2015. By applying the Autoregressive Distributed Lag approach and Toda and Yamamoto test, we found evidence to conclude that the quality of the informal institution harms the size of the shadow economy. The results of the causality test show that there is a unidirectional causality running from the shadow economy and the quality of the informal institution to foreign direct investment attraction in Vietnam. Political solutions need to be implemented carefully to counter the harmful effects of the shadow economy. Policymakers should adopt several economic policies to improve the ‘human capital’ and drive the shadow economy into the formal economy.

The paper aims to investigate the interactions between rule of law, economic growth and the shadow economy in 18 selected transition economies. This study uses annual data over the period 2002-2015 for 18 transition countries to estimate the effects of rule of law and other factors on the size of shadow economy. The transition country group is classified based on International Monetary Fund resources and is selected on the basis of the availability of data. The data examined in this research are derived from the World Bank, Worldwide Governance Indicators project and Working Paper from International Monetary Fund. This study employs GMM method. The results show that the economic growth indicators have negative and statistically significant impact on the shadow economy. Additionally, these results also reveal that in transition countries the size of shadow economy is negatively related to the quality of rule of law. However, the findings of this research also point out that there are positive relationships between inflation, public expenditure and the size of shadow economy. Hence the results from this study suggest that the size of shadow economy could be controlled by improving the effectiveness of rule of law and the growth of economy particularly in transition countries.