We analyze the desirability of level playing fields in international financial regulation. In general, level playing fields impose the standards of the weakest regulator upon the best-regulated economies. However, they may be desirable when capital is mobile because they counter a cherry-picking effect that lowers the size and efficiency of banks in weaker economies. Hence, while a laissez faire policy favors the better-regulated economy, level playing fields are good for weaker regulators. We show that multinational banking mitigates the cherry-picking effect, and reduces the damage that a level playing field causes in the better-regulated economy.