Essay寫作中每年必考Alevel經(jīng)濟考點elasticity的解析

 

　　如果對AS的經(jīng)濟真題進行分析，我們會發(fā)現(xiàn)，在Paper 2的essay里，elasticity（彈性）幾乎是每年必考Alevel經(jīng)濟考點，因此如果對這塊知識點掌握得很好，那么AS階段的alevel經(jīng)濟Essay想拿高分其實很簡單！

　　讓我們來看一道2018年冬季Section B的真題。

　　我們在動筆寫essay之前要有一個邏輯框架。對于這種8分且命令詞是explain的題，其答題框架很簡單，大致如下：

　　Structure：

　　P1：Define key terms（PES）

　　Body P2：Explain factor 1

　　P3：Explain factor 2

　　P4：Explain factor 3

　　有了框架之后，就需要考慮內(nèi)容該寫什么了。這道題很常規(guī)，是相關(guān)章節(jié)基礎(chǔ)知識點的考察，學(xué)生們只要掌握好PES的概念、計算公式，經(jīng)濟意義和影響PES那幾大因素就能做答了，當(dāng)然我們在essay的寫作中，一定要注意內(nèi)容的完整性還有不要答偏題了。以下答案供同學(xué)們參考學(xué)習(xí)。

　　Define：Price elasticity of supply[PES]measures the degree of responsiveness in quantity supplied of a good due to a change in the price of the good itself.It is measured by PES=%?QS/%?P.A good is said to be elastic PES when a change in price leads to a more than proportionate change in the quantity supplied.The value of PES is more than one.Inelastic PES means a change in price will lead to a less than proportionate change in quantity supplied.The value of PES is between zero and one.

　　Body

　　1.Factor:Availability of spare capacity.When the level of production is at,or near,the level of full capacity,then,the supply of the good is likely to be inelastic PES.An increase in price will not be follow by the increase in supply due to capacity constraint.For example,if the factory is producing at full capacity,and increase in price of the good will not lead to increase in supply.The capacity will need to be raised before increase in output can materialized.

　　2.Factor:Time of production.If the good in question require a long period of production,for example agricultural good,then,the supply of the good is likely to be inelastic.The supply of the good cannot be increased in the short term,as time is required for the output to grow.Manufacturing goods,in general,are more elastic in PES due to the shorter period in the production process.

　　3.Factor:Mobility of factors.If the factors of production can be easily switched from producing one good to another,then,the PES will be more elastic.A higher price in jeans(clothing)can be matched by higher quantity as the material and machine can be easily switched to produce jeans from other clothing products.While an increase in the price of rubber,cannot be matched by increase in supply,as the rubber trees can only produce rubber and cannot produce any other things.Oil palm plantation can be switched to rubber plantation,though it will incur high cost and long period.

　　關(guān)于Alevel經(jīng)濟考點elasticity的講解就到這里了，如果同學(xué)們在Alevel學(xué)習(xí)中還有什么問題，歡迎隨時咨詢我們！