贸易摩擦、宏观经济波动与经济开放程度的选择

本文构建一个包含关税冲击以及外汇风险溢价的两国开放经济DSGE模型,创新地揭示了关税冲击造成实际汇率波动的“直接效应”与“间接效应”,刻画了关税变动、贸易条件与实际汇率之间的动态关系与作用机制。我们深入分析了不同经济开放程度下贸易摩擦造成的宏观经济波动以及经济福利损失。模拟结果表明,在一定贸易开放程度下,外国加收关税一方面会导致本国贸易条件恶化,引发出口及产出下降;另一方面会导致本国汇率贬值,引发出口及产出增长。关税冲击发生后短期中汇率贬值效应占优,本国产出会出现小幅上升,随后贸易条件恶化效应逐步显现,产出持续下降。福利分析结果表明,本国适度提升贸易开放度,虽然经济福利损失会小幅上升,但福利损失增加幅度小于外国,会在贸易摩擦竞争中形成相对优势;如果本国过度提高贸易开放度,则会导致本国福利损失大幅增加,并且大于外国福利损失增幅,会在贸易摩擦竞争中形成相对劣势。因此,应适度逐步有序地提升贸易开放度。此外,本国适度推进资本账户开放的政策能够改善贸易条件,促进本国经济增长。

Trade Friction,Macroeconomic Fluctuations,and the Choice of Economic Openness

Trade friction between China and the United States (US) broke out in early 2018. We can foresee that with the gradual improvement of China's international economic status, Sino-US economic and trade relations will continue to be affected by various forms of friction and conflict. Moreover, it is likely that such frictions and conflicts will exist cyclically in the long run, which will eventually have significant and profound impacts on China's macro-economy. Therefore, it is necessary to analyze the following questions in depth: how will trade frictions affect China's macro-economy？ To what extent can China open up its economy?According to international trade theory, a country can impose tariffs to improve its terms of trade and promote net export growth. Therefore, tariff measures are often used as the most direct policy tool when trade frictions occur between two countries. This article introduces tariff shocks, foreign exchange risk premiums, and monetary policy cost channels into a two-country open economy dynamic stochastic general equilibrium model to study the macroeconomic fluctuations caused by trade frictions and analyze relevant policy options for the economic opening of markets. This article decomposes the real exchange rate fluctuations caused by tariff shocks into “direct effects” and “indirect effects” and clarifies the transmission channels and theoretical mechanisms through which tariff shocks affect the terms of trade and the real exchange rate.First, the log-linearization of the real exchange rate equation shows that an increase in tariffs directly triggers the devaluation of the domestic currency. However, these exchange rate changes cannot fully offset the price distortion caused by tariff shocks. Second, after expressing the terms of trade as an equation of the relative output levels of the two countries, tariffs, and foreign exchange risk premiums, we find that tariff shocks deteriorate the terms of trade, which triggers the appreciation of the domestic currency. Therefore, tariff shocks affect the real exchange rate through direct and indirect channels.The results of impulse response analysis show that tariff shocks change the terms of trade and the real exchange rate. Under the current status of China's trade openness, foreign tariffs will not only deteriorate the country's terms of trade, leading to a decline in exports and output, but will also depreciate the country's exchange rate, leading to an increase in exports and output. Overall, for the macro-economy, tariff shocks will induce a minor increase in domestic output and a decline in home inflation, as well as a decline in foreign output levels and an increase in foreign inflation.Moreover, if the domestic government strengthens its control over cross-border capital flows during trade frictions, the terms of trade will deteriorate and cause the real exchange rate to appreciate, which will negatively affect exports and output. A loose monetary policy can directly stimulate output growth and, simultaneously, indirectly increase domestic economic output by depreciating the exchange rate and improving the terms of trade.The results of economic welfare analysis suggest that the government's choice of trade openness and capital account openness significantly affect macroeconomic fluctuations. First, a moderate increase in domestic trade openness leads to a slight increase in economic welfare losses, while the foreign country faces greater welfare losses; an excessive increase in domestic trade openness leads to a sharp increase in domestic welfare losses, which reach a value greater than the welfare losses incurred by the foreign country. Second, in trade frictions, a moderate relaxation of capital controls improves the terms of trade, which depreciates the real exchange rate and increases output. Finally, an increase in foreign tariffs will trigger the devaluation of the domestic currency. The moderate depreciation of the domestic currency helps hedge against the negative impact of tariffs, increase exports, and boost domestic economic output. In conclusion, in the face of the trade frictions, the domestic government should adhere to the principle of increasing trade openness within an appropriate scope and steadily promote capital account liberalization to avoid substantial economic welfare losses. In addition, implementing a loose monetary policy and relaxing the exchange rate daily trading band can help mitigate the negative impacts of trade frictions.