贸易条件将有所改善，但可以说贸易差额是否会因贸易商因鱼价波动造成的不确定性而变化（价格因货币贬值导致需求拉动价格上涨而下降）。如果他们应该选择专注于汽车，机械或移动电话等成品，这些产品可以说比鱼更具弹性，他们可能无法从这些产品的比较优势中受益，孟加拉国是一个具有比较优势的发展中国家在鱼。这些新产品的质量可能达不到进口商的标准。这种质量的不确定性肯定会影响到这个国家。即使马歇尔 – 勒纳条件得到满足并且经济中存在备用能力，一个国家的公司也可能无法在汇率变化后立即增加供应。这是因为，在短期内，商品和服务的需求弹性被认为是相对缺乏弹性的。在这些情况下，贸易差额实际上可能会在改善之前恶化。这经常发生，它有一个名字;它被称为J曲线效应（当贬值导致BOT首先恶化然后改善）。为什么贸易逆差最初会增加？记住这些变量，价格（P）和数量（Q）。当汇率下降时，减少的数量和上涨的数量，而上涨的价格和下跌的价格。在短期内，价格倾向于主导数量效应，因此贸易逆差平衡变得更大（或盈余减少）。然而，最终，数量效应往往超过P效应，因此贸易逆差平衡变得更小。这解释了贸易逆差平衡的初始增长，随后是曲线向上。如果进口价格上涨和价格下降导致当地商品需求（支出转换）和需求上升，那么在一定时期内，汇率贬值的影响可能会被侵蚀掉。增加的出口收入将作为国内循环收入的注入。通过乘数，它可以产生更多的收入。消费和储蓄将增加，利率将下降。投资将增加（由于货币贬值），从而推动经济增长。资源的使用将增加（将PPF转移到曲线上或接近曲线的点）并且该国享有更高的生活水平。如果该国已经处于充分就业和收入水平，将导致通货膨胀（商品和服务价格普遍上涨）再次抬高价格，改善贸易条件并再次影响贸易平衡。在主要在亚洲国家进行调查后，发现了这种趋势，并将其称为S曲线效应，作为J曲线效应的延伸（Backus，Kehoe和Kydland 1995）。注意曲线的相似形状与x轴反射的sin图形;我相信，这些调查结果之间没有任何关系。作为结论，如果我们考虑到其他因素，例如国内和国外的通货膨胀率弹性，我们只能确定贸易条件的恶化是否会导致贸易差额的恶化。政府应该采取某些步骤和政策来操纵贸易条件和贸易平衡，以实现国家的更大利益。
The terms of trade will improve, but it can be said that the trade balance will change due to the uncertainty caused by traders’ fluctuations in fish prices (prices are declining due to currency depreciation, which drives demand to drive prices up). If they should choose to focus on finished products such as cars, machinery or mobile phones, these products can be said to be more flexible than fish, they may not be able to benefit from the comparative advantages of these products, Bangladesh is a comparative advantage in developing countries in fish . The quality of these new products may not meet the standards of importers. This quality uncertainty will definitely affect this country. Even if Marshall-Lerner conditions are met and there is spare capacity in the economy, companies in one country may not be able to increase supply immediately after exchange rate changes. This is because, in the short term, the elasticity of demand for goods and services is considered to be relatively inelastic. In these cases, the trade balance may actually deteriorate before it improves. This happens often, it has a name; it is called the J-curve effect (when the depreciation causes the BOT to deteriorate first and then improve). Why does the trade deficit initially increase? Remember these variables, price (P) and quantity (Q). When the exchange rate falls, the amount of the decrease and the amount of the increase, while the price of the rise and the price of the fall. In the short term, prices tend to dominate the quantitative effect, so the trade deficit balance becomes larger (or the surplus is reduced). However, in the end, the quantitative effect often exceeds the P effect, so the trade deficit balance becomes smaller. This explains the initial increase in the trade deficit balance, followed by the curve up. If import prices rise and prices fall, resulting in local commodity demand (spending) and rising demand, the impact of exchange rate depreciation may be eroded for a certain period of time. Increased export earnings will be used as an injection of domestic recycling revenue. It can generate more income through multipliers. Consumption and savings will increase and interest rates will fall. Investment will increase (due to currency depreciation), thereby driving economic growth. The use of resources will increase (transfer PPF to or near the curve) and the country enjoys a higher standard of living. If the country is already at full employment and income levels, it will lead to inflation (the general rise in prices of goods and services) to raise prices again, improve terms of trade and once again affect trade balance. This trend was discovered after investigations in mainly Asian countries and was referred to as the S-curve effect as an extension of the J-curve effect (Backus, Kehoe and Kydland 1995). Note the similar shape of the curve and the sin graph of the x-axis reflection; I believe there is no relationship between these findings. As a conclusion, if we consider other factors, such as the elasticity of inflation at home and abroad, we can only determine whether the deterioration of the terms of trade will lead to a deterioration of the trade balance. The government should take certain steps and policies to manipulate the terms of trade and trade balance to achieve greater national interests.