经济学的学习过程中，大家一定不要忽视对专业定义和相关解释的记忆，这些不仅是组成课程的重要部分，更是可以用作论文写作素材的资源。以防大家在写论文时有思路没内容，小编为大家整理了中英对照版本的Alevel经济学模块定义汇总，本篇是自由贸易版块的上篇，持续关注，看下篇哦~

Some definitions 一些定义

Before we plough into the case for free trade, it is important that we define a few terms. 在我们深入讨论自由贸易的问题之前，重要的是我们要定义几个术语。

Absolute advantage 绝对优势

A country has anabsolute advantageover another country in the production of a certain good if, for a given amount of resources, it can produce more of the good than its competitor. Another way of looking at it is that the country with the absolute advantage can make the same amount of the good with fewer resources. Basically, it is when one country is better at making a given good than another country. See the next Learn-It for a numerical example.

一个国家在生产某种商品时对另一个国家具有绝对优势，如果在一定数量的资源下，它能比其竞争者生产更多的商品。另一种看法是，具有绝对优势的国家可以用较少的资源生产同样数量的商品。基本上，它是指一个国家比另一个国家更善于制造某种特定的商品。请看下一个学习资料中的数字例子。

Comparative advantage 比较优势

The theory ofcomparative advantagetakes absolute advantage a stage further. Even if a country is so bad at using a given set of resources that it is worse at making all goods than another country, it will still have a comparative advantage in the production of at least one good. This means that there will be at least one product where it isrelativelybetter at producing, even though inabsoluteterms it is the worst at making everything.

比较优势理论把绝对优势又向前推进了一个阶段。即使一个国家在使用一组特定的资源方面非常糟糕，以至于它在制造所有商品方面都比另一个国家差，它仍然会在生产至少一种商品方面具有比较优势。这意味着，至少会有一种产品，它在生产方面相对较好，尽管从绝对意义上讲，它在生产所有产品方面是最差的。

The terms of trade 贸易条件

Put simply, theterms of tradeare the 'terms' (or price) agreed when two countries trade. You will see that it is important to understand this concept when we look at numerical example of trade between countries below.

简单地说，贸易条件是两个国家进行贸易时商定的 "条款"（或价格）。当我们看下面国家间贸易的数字例子时，你会发现理解这个概念很重要。

Examiners often set multiple-choice questions on the terms of trade. You are expected to work out what will happen to the terms of trade if, say, the value of the pound rises. The 'terms of trade' for a country as a whole is the ratio of export prices to import prices.

考官通常会设置关于贸易条件的多项选择题。你应该计算出如果英镑升值，贸易条件会发生什么变化。一个国家整体的 "贸易条件 "是出口价格与进口价格的比率。

The index of export prices and the index of import prices are calculated in the same way as theRetail Price Index (RPI). A weighted average is calculated using the prices of thousands of exports and imports. Remember that an index does not have any units. The series of numbers are simply used to make comparisons of the average price level (for exports and imports in this case) over different time periods (monthly or yearly).

出口价格指数和进口价格指数的计算方式与零售价格指数（RPI）相同。使用数以千计的出口和进口的价格来计算加权平均。记住，一个指数没有任何单位。一系列的数字只是用来比较不同时间段（每月或每年）的平均价格水平（本例中为出口和进口）。

In the example above of a rising pound (ceteris paribus) the prices of exports will rise, and the prices of imports will fall. The terms of trade, therefore, will rise (the top part of the fraction is rising and the bottom part is falling, so, overall, the fraction rises).

在上述英镑上涨的例子中（其他情况下），出口价格将上升，进口价格将下降。因此，贸易条件将上升（分数的上半部分在上升，下半部分在下降，所以，总体而言，分数在上升）。

以上是小编为大家总结的Alevel经济学的关键定义。希望对大家有所帮助，祝各位同学学业有成金榜题名！如有更多Alevel课程辅导的需要，欢迎联系在线客服老师，会获得更专业的指导~