Two months after he was sworn into office, President Joe Biden tasked Vice President Kamala Harris with addressing the “root causes” of the migration crisis. As Democratic Party theory of the border crisis goes, Harris’s efforts have not been a complete failure. She has raised billions of private sector dollars for economic development in Central American countries.

The disqualifying fault with the “root cause” theory, however, is that it misdiagnoses the problem. Migrants aren’t spending thousands of dollars to come to the United States because they are poor. If anything, these nations are already becoming wealthier. That’s why they can afford cellphones and smuggler fees to come to the U.S. Migration can be a phenomenon of economic success, not merely of failure.