BBC correspondent in Dhaka
A migration conference in Bangladesh has concluded that money sent home by economic migrants can significantly boost development and reduce poverty.
Bangladeshi migrant workers queue for Saudi visas in Dhaka
The forum heard that migration had benefited women, the poor and governments alike, although many Asian administrations still view it with suspicion.
Figures produced showed remittances from overseas migrant workers accounted for more than half of Bangladesh's development budget, 40% of India's trade deficit and most of Pakistan's foreign-exchange sources.
In many cases the remittances exceeded funds given to their countries by Western donors.
The conference, which ends on Wednesday, is being held in the Bangladeshi capital, Dhaka.
It has been jointly hosted by the British Department for International Development (DFID) and the Bangladeshi Refugee and Migratory Movements Research Unit.
The conference heard that there are between six and seven million Asians who work abroad, earning more than $20bn a year.
Nearly two million Asian workers leave their country every year to work abroad.
Overseas migrants aid Bangladesh development, the forum heard
However, the vast majority of migrants stay within their own country.
Some go from rural areas to city shanty towns but more move from one rural area to another in search of work.
In many Bangladeshi villages, 80% of income comes from outside sources.
Delegates said this was a process that should be encouraged rather than stifled.
Paul Ackroyd, head of DFID Bangladesh, said: "Although there is a negative side to migration, it is nonetheless a vital tool for development in south and east Asia and can benefit both the sending and the receiving countries."
However, many governments in Asia fear that migration means a brain drain and human trafficking on the one hand and the arrival of illegal immigrants on the other.
Many delegates argued against this negative perception, saying that if Asian countries did not encourage migration, they would stagnate and die.
But the conference did acknowledge a darker side to migration.
Women, who make up around 50% of Asia's international migrants, have been in many cases exploited.
They face demands for higher payments from recruitment agents and are often physically and sexually assaulted by employers.
The conference concludes on Wednesday with a series of recommendations to help migration benefit the poor.