Research on the Source of China's Foreign Trade Surplus——General Theoretical Model Construction and Empirical Test

Based on permanent income theory,from the perspective of demand,this paper constructed a theoretical model which included main explanations on China international trade surplus.And the explanations are exchange rate,insufficient consumption,resource and invest-saving gap.The model pointed out that insufficiency of expected income is the origin of trade surplus.The influence of exchange rate on trade surplus was uncertain.Insufficiency of investing chance and defect of financial system expanded the trade surplus.At the end,this paper pointed out four suggestions which were improving social security system,developing legal institutions,curbing inflation,and keeping exchange rate smooth and steady.