To some the word "immigration" evokes an image of people standing in line at Western Union, waiting to wire money home to families for groceries and clothing. It happens thousands of times each day all over the world. All those remittances — the small amounts of cash wired across borders — add up to a whopping $300 billion a year.

Dilip Ratha believes this $300-billion industry can play an important role in international development. He's a World Bank employee who is working to make it easier for migrants to transfer money and direct the cost savings towards economic development in their own countries.

Skeptics argue that if remittances equaled development, Mexico would look like Switzerland. Ratha might argue that without remittances, Mexico's economy might look a whole lot worse. His new paper suggests that Africa could add as much as $3 billion to public coffers just by reducing the costs that migrants pay to send remittances. (Currently, charges on these cross-border money transfers can be as high as 10 percent.)

Ratha hopes to prove that hundreds of billions of remittance dollars can be funneled toward poverty alleviation by making simple policy changes.

His personal story has shaped his beliefs. In the U.S., he earns a salary that is 100 times what he could have earned in his birthplace of India, and his own remittances have helped build schools and pay medical bills there.

And while the negative impacts of immigration often make headlines, Ratha stresses that there are costs of not immigrating, too — costs borne by people living in poverty and by everyone in the global economy.