2013 remittances from US to Honduras, El Salvador, Guatemala, Nicaragua, and Mexico. Chart from Howard G. Buffett presentation
page 15, "Financial incentives"
"Many immigrants send money back to family members in their home countries. These remittances play an important role in the livelihoods of the individuals who receive them and the economies of the receiving countries. 1, 2"
"1. The World Bank Remittances
2. USAID website for ODA data"
March 17, 2015, "Written Testimony Submitted by Howard G. Buffett, Chairman and CEO of the Howard G. Buffett Foundation, to the Senate Homeland Security and Government Affairs Committee Hearing on “Securing the Southwest Border: Perspectives from Beyond the Beltway”," The Howard G. Buffett Foundation
Note: Following is how I got to the above testimony: