本研究使用越南中央統計總局(General Statistical Office, GSO) 2000至2008年廠商普查資料，分析外國企業與本土企業之間的薪資差異，並觀察外人直接投資的進入是否提升本土企業薪資水準，也就是產生薪資外溢效果，然而法律規範的四類區域不同最低薪資造成薪資外溢效果難以分辨，加入WTO之後讓第二區之薪資外溢效果更上一層樓，第一區卻沒有發生如此現象，這其中又是什麼樣的因素導致呢?
根據外資進駐越南各省份的程度不一，資源競爭性也就跟的改變，即使整體平均薪資提升，仍可能存在同產業內的廠商薪資差異擴大的問題或產生排擠效果，進一步探討是否造成各產業薪資發展不均衡的現象。有趣的是，對於各省每年薪資在外資與本土企業之間的落差，我們原先認為差距越大代表薪資提拉的壓力可能越大，但結果出乎意料，在省內控制外資產出占比變數後，省內的差距越大竟然會帶來整體薪資降低之現象，表示即使外資進駐會拉升薪資水平，「兩極化」現象在省內卻會惡化整體薪資水平。
整體上，相對於國營企業而言，外資的進駐對於私人企業有較重大的薪資外溢影響，符合國營企業穩定的薪資現象。

This paper examines the effect of foreign direct investment (FDI) in Vietnamese manufacturing on wages in locally owned Indonesian manufacturing plants. We use manufacturing census data for 2000 to 2008 undertaken by the General Statistical Office (GSO) to analyze the extent of wage differentials between foreign multinational enterprises, state-owned enterprises and domestic private firms. It is difficult to distinguish the wage spillover effect when the government setting a minimum wage in distinct regions, even different rules between foreign multinational enterprises and local firms.
The impact of foreign direct investment on overall wages depends not only on how high the foreign firm wages are, but also on their effect, if any, on wages in locally owned firms. After 2007, Vietnam became as a member of the WTO and the effect of the spillover in the second district is higher. However, it has not apparently happened in the first district.
According to the degree of foreign investment in the provinces of Vietnam, the competitiveness of resources is changed, and even if the overall average salary increase, there may still be the expansion of the differences in salary within the industry, or a squeeze effect to the inefficient firms. In order to further explore whether the industry wage growth is not balanced, we inspect the direction of the influence of the salary gap in the provinces every year. We originally thought that the greater the gap meaning the salary suffers the pressure to increase, but the result was unexpectedly. The larger the gap in the province will lead to a reduction in the overall salary, indicating that even if foreign investment will pull up salary levels, "polarization" phenomenon in the province will deteriorate the overall salary level.
On the whole, relative to the state-owned enterprises, foreign investment makes a greater impact on wage spillovers in the private sector, in line with the state-owned enterprises has a stable salary appearance.

參考文獻
Aitken, B., Harrison, A., & Lipsey, R. E. (1996). Wages and foreign ownership A comparative study of Mexico, Venezuela, and the United States. Journal of international Economics, 40(3-4), 345-371.
Blomström, M. (1986). Foreign investment and productive efficiency: the case of Mexico. The Journal of Industrial Economics, 97-110.
Findlay, R. (1978). Relative backwardness, direct foreign investment, and the transfer of technology: a simple dynamic model. The Quarterly Journal of Economics, 92(1), 1-16.
Forni, M., & Paba, S. (2002). Spillovers and the growth of local industries. The Journal of Industrial Economics, 50(2), 151-171.
Herzer, D., Hühne, P., & Nunnenkamp, P. (2014). FDI and Income Inequality— Evidence from Latin American Economies. Review of Development Economics, 18(4), 778-793.
Kokko, A. (1994). Technology, market characteristics, and spillovers. Journal of development economics, 43(2), 279-293.
Kokko, A. (1996). Productivity spillovers from competition between local firms and foreign affiliates. Journal of international development, 8(4), 517-530.
Kokko, A., Tansini, R., & Zejan, M. C. (1996). Local technological capability and productivity spillovers from FDI in the Uruguayan manufacturing sector. The Journal of Development Studies, 32(4), 602-611.
Lipsey, R. E., & Sjöholm, F. (2004). FDI and wage spillovers in Indonesian manufacturing. Review of World Economics, 140(2), 321-332.
Nguyen, K. T. (2014). Economic reforms, manufacturing employment and wage in Vietnam.
Nguyen, K. T., & Ramstetter, E. D. (2017). Wage differentials among ownership groups and worker quality in Vietnamese manufacturing. Global Economic Review, 1-19.
Nunnenkamp, P., Schweickert, R., & Wiebelt, M. (2007). Distributional effects of FDI: how the interaction of FDI and economic policy affects poor households in Bolivia. Development policy review, 25(4), 429-450.
Sjöholm, F. (1999). Technology gap, competition and spillovers from direct foreign investment: evidence from establishment data. The Journal of Development Studies, 36(1), 53-73.
Sjöholm, F., & Takii, S. (2006). Multinational Companies and Exports in Indonesian Manufacturing. Multinationals in Indonesia and Thailand: Wages, Productivity and Exports. Hampshire, UK: Palgrave-Macmillan, 173-193.
Trung Kien, N. (2014). Employment Transformation in the Vietnamese Economy in Light of the Lewis-Fei-Ranis Growth Model of A Labor-Abundant Economy. Journal of Economics and Development, 16(3), 49.
Wang, J. Y., & Blomström, M. (1992). Foreign investment and technology transfer: A simple model. European economic review, 36(1), 137-155.