An income-tax hike will reduce private demand (unless one believes in perfect Ricardian equivalence), including demand for other countries’ exports. Other macroeconomic policies of all kinds influence the current-account balance.
还可以跟进一步。所得税提高会降低私人需求（除非你相信完美李嘉图等价），包括对其他国家出口的需求。其他各种宏观经济政策也都可以影响经常项目余额。