The United States and Canada are far more integrated than most people think. In fact, a merger between the two countries isn’t just desirable—it’s inevitable. We share more than just the world’s longest border. We share the same values, lifestyles and aspirations. Our societies and economies are becoming similar in significant ways.

The euro crisis has put most people off currency unions. But not in Africa, it seems. In November the leaders of five countries of the East African Community (EAC) agreed to form a monetary union within ten years. A month before West African politicians agreed on a plan to introduce a new shared currency, the eco, over the next few years. It should eventually subsume West Africa’s existing currency bloc—but not its central African cousin.