But a dire shortage of US teachers means some schools are taking drastic measures -- like hiring teachers from half a world away. So schools like Casa Grande Union High have hired several Filipino teachers using J-1 visas. Alvarado is one of several Filipino teachers in their fourth year at Casa Grande teaching science -- a notoriously hard subject to fill with US teachers. In some cases, Filipino teachers pay an upfront fee, and the agency sets up the online interviews, tests and paperwork. But why do many Filipino teachers get selected to go to the US?