Traditional international trade theory only explained one aspect of the reasons why international trade happened. The emergence of " the Leontief Paradox","Linder trade phenomena " and intra-industry trade greatly shaken the dominant foundation of the traditional international theory. Thus, neo-trade theory which focused on economy of scale, product differentiation and imcompetition was gradually built up on the basis of the criticism about traditional theories. Neo-trade theory could give a good explanation to a series of post-war international trade, but they could only explain the other aspect of the reasons why international trade happened. All along, the attempt that economists establish a united analysis framework to have a full explanation to all the trade phenonmina has failed.On the basis of our predecessors'research, this paper, from the perspective of the factors that practically influence international trade, considers supply and damand factors (including transition costs) simutinuesly.By using the methods of econophysics and Newton's gravity model, the paper sets up the"motive and drag force"model of international trade with three key concepts: unit cost of production, effective marginal utility and transaction costs. In order to be more realistic, the model puts forward to "incomplete information","incomplete rational men"assumptions as well as "imcompetitive conditions" and "returns to scale".The paper tries to explain the reason why international trade happened by using the"motive and drag force"model. In addition, it tries to analyze the whole international trade in the history, including"why there were no international trades thousand years ago?","How a trade became foreign instead of domestic?","Why international trade goes from inter-industry to inner-industry?". Besides these, this paper also talks about laissez-faire and protectionism.In the end of the paper, it gives policy proposals on writer's point of view. |