potentially why they choose to export instead of invest in domestic industry. its usually more lucrative but fleeing capital is bad for an economy.  again the single exception to this is the us and thats because of our reserve currency status. we force the trade in our currency which alleviates the capital flight issue (although it is still an issue, just not the same type. currency stuck in the foreign markets doesnt help the domestic economy, it just helps the domestic currency).
United States