President Hugo Chávez greeted the news of Venezuela’s entry into the Mercosur customs union by announcing the creation of a “Bond of the South” issued jointly with Argentina. It is doubtful that the joint government bond will float; such a bizarre arrangement has never been tried before. But perhaps Argentina is seeking to reap a bit of what it has sown: Venezuela has already realized healthy returns on the nearly $3 billion it has invested in Argentine debt since last year. Venezuelan bankers also find Argentina’s bonds handy as a way to convert bolivares into dollars, circumventing Chávez’s currency controls.