This paper extends the balance-of-payments-constrained (BoPC) growth model and Thirlwall's law to include the terms of trade with and without capital flows. Without capital flows a positive (negative) change in the terms of trade by improving (worsening) export performance can ceteris paribus augment (reduce) the rate of growth of an economy compatible with balance of payments' long-run equilibrium. With the inclusion of capital flows the BoPC dynamics become more complex. Assuming no changes in the real exchange rate and in the import elasticity of demand, an improvement in the terms of trade can increase the level of the external deficit compatible with BoPC growth. This results from the terms-of-trade effects on the purchasing of exports and on foreign-capital inflows. The positive effect of an improvement in the terms of trade may be partially offset by an appreciation of the real exchange rate and an increase in the import elasticity of demand, when the model is extended to allow for such interactions in the analysis.

中文翻译：

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瑟尔沃尔定律和贸易条件：国际收支约束增长模型的简约扩展

本文扩展了国际收支约束 (BoPC) 增长模型和瑟尔沃尔定律，以包括有和没有资本流动的贸易条件。在没有资本流动的情况下，贸易条件的积极（消极）变化通过改善（恶化）出口表现可以在其他条件不变的情况下增加（降低）与国际收支长期均衡相适应的经济增长率。随着资本流动的加入，BoPC 的动态变得更加复杂。假设实际汇率和需求的进口弹性没有变化，贸易条件的改善可以增加与 BoPC 增长相适应的外部逆差水平。这是贸易条件对出口采购和外资流入的影响的结果。