The article looks at how foreign investment affects economic growth and domestic investment in different regions of Vietnam. By analyzing data from Vietnamese provinces, the researchers found that in areas with high foreign investment, it leads to economic growth and boosts domestic investment. However, in regions with less foreign investment, economic growth actually attracts more foreign investment, and foreign investment tends to reduce domestic investment. This shows that foreign investment has different effects depending on the region, with a tendency to cluster in areas with existing foreign investment.