The study looked at what makes certain US counties attractive to foreign companies setting up new plants. They found that places with more previous foreign investments, larger markets, better access, and more land tend to attract more foreign investment. On the other hand, higher costs for things like labor and materials can discourage foreign companies from coming in. Surprisingly, strict environmental rules don't seem to scare off foreign investors. This information is important for policymakers because foreign investment is expected to grow as the world economy becomes more connected.