let them blab for a while then show them my university ID and tell them my visit is explecitly to research and write a report about the tourism industry, offering to call my 'advising professor' is they oblige...the illiterate bunch soon becomes my friend: I get to skip the immigration line and they carry my luggage free of charge. It has worked so well and I get such a good service that way, I now deliberatly act suspecious so as to beg them to stop me..
..I get better service that way!
(AILA is the airport I generally use)