Question is how much permanent migrant send money back home and how much temporary migrants? If you look into stat most of the foreign remittances are comming from middle easten countries and India (temporary migrants who will eventually to go back home) and least from countries like USA and UK (where people are seeking permanent migration). Not to forget migration to USA and UK is the permanent brain drain for the country. Also just imagine how much money has been invested in creating these man power back in home (just calculate the cost of education alone to become professional like doctors and engineers). I agree most of the time its individual's parents money unless they have got scholarships, but still it is comming out from national economy. And yet the people who are advocating for this dual citizenships are these permanet migrants looking to settle down is USA and UK. Just an alternative thought...