What are the long-term implications of a invasion and creation of a foreign closed-loop economy within an existing local economy?

When a foreign entity, group of companies, or a full logistics chain from another country "invades" a local market and sets up its own parallel, self-sustaining system, an enclave economy that doesn't really "leak" wealth back into the local community, in a true foreign closed-loop system, the foreign entity brings its own raw materials, uses its own specialized technology, and sends all the profits back to its home country, so what are short-term and long-term consequences or benefits for the home country?