[soapdog]

That is not how it was taught to me. Expat is when your job moves you to a new country, as in "you're an expatriate employee". Immigrant is when you move for your own reasons. Expats are expected to come back to their original country, or move to a third one at some time. Immigrants are establishing themselves in the new country.

[ben_w]

I have always understood it to be an example of English irregular language: “I am an expat, you are an immigrant, they are economic migrants.” —https://en.m.wikipedia.org/wiki/Emotive_conjugation