This study considers the effects of financial development on output in a panel cointegration framework, focusing on the implications of trade and financial openness. Our analysis indicates that after controlling for cross‐sectional dependence, the typical relationship between finance and output does not hold in the long run. This relationship, however, is re‐established once we account for economic openness. While trade openness emerges as more important for developing countries, financial openness is more important for advanced economies. In the long run, causality runs from financial development to output in the advanced economies, while in developing economies causality is bidirectional. There is no short‐run causality between financial development and output, however.