push factornoun [ C ]
uk/ˈpʊʃ ˌfæk.tər//ˈpʊʃ ˌfæk.tɚ/something that makes people want to leave a place or escape from a particular situation:
Instead of a fruitless attempt to eliminate illegal immigration, rich countries could focus on reducing the push factors that force some to flee - chiefly poverty and persecution.
Compare
pull factor