[Econ衝**] 2017 DSE 經濟科試前討論區

Btw你地寫彈性條式出黎睇下

(%change in Qd)/(%change in price)
唔啱？

姐係
((Q'-Q)/Q)/(P'-P)/P)？

有幾多巴絲係咁學？

書條式一大舊嘅

風扇

Btw你地寫彈性條式出黎睇下

(%change in Qd)/(%change in price)
唔啱？

姐係
((Q'-Q)/Q)/(P'-P)/P)？

有幾多巴絲係咁學？

書條式一大舊嘅

中意咪入條programme計
Btw mid point 果個計法係咪out c?

Btw你地寫彈性條式出黎睇下

(%change in Qd)/(%change in price)
唔啱？

姐係
((Q'-Q)/Q)/(P'-P)/P)？

有幾多巴絲係咁學？

書條式一大舊嘅

中意咪入條programme計
Btw mid point 果個計法係咪out c?

睇錯 自膠

Btw你地寫彈性條式出黎睇下

(%change in Qd)/(%change in price)
唔啱？

姐係
((Q'-Q)/Q)/(P'-P)/P)？

有幾多巴絲係咁學？

書條式一大舊嘅

100%同埋2可以約走架

約走左之後為何要除(q1+q2)
而唔係除q1 ?

呢條formula叫mid point formula，係計arc嘅Elasticity
係同傳統嘅percentage change有唔同，至於點解要咁做，dse唔會問吧總之比咗兩個p同兩個q叫你計elasticity就要用呢條mid point formula

但係，如果題目直接比左%change in qd同%change in price你嘅話，就直接將前者除以後者

唔該

依條明呀 岩岩都做錯左 淨係諗highest valued option forgone 然黎以為淨係B 但其他我就真係諗唔通 都似成日般龍門咁

好亂 都唔知佢個definition想點 又話highest valued option forgone但又要計埋俾左嘅錢

1st choice: A
2nd choice: B
3rd choice: C
咁嘅情況 你揀A嘅話 OC就會係B嘅value

但如果題目淨係比左一個choice(A)你
問你揀A嘅OC係乜
咁就會係揀A背後所出嘅錢 時間 同其他non-monetary cost

同樣道理
有個人用$30000買左樣野(當係A)個題
1st choice: A
2nd choice: B
但當B對買野個個人黎講嘅value係細過$30000嘅時候 就會變左：
1st choice: A
2nd choice: $30000 cash
3rd choice: B
咁OC就會係$30000
而當個$30000+value of B=value of A嘅時候
咁你揀A 已經係放棄左both B and $30000 cash
所以 當題目冇講到明value of B係幾多嘅時候 你唔知B定$30000 cash係個個人嘅2nd choice(highest-valued option forgone) 所以OC就會包埋個$30000

有個人own a house個題
paid a sum to buy a house已係sunk cost
唔計入OC
真正嘅OC係rental income forgone(自往緊冇得租比人收租)

有錯請指正

好清晰

其實opportunity cost = explicit cost + implicit cost?
Implicit cost 同 opportunity cost 係有啲混亂

大家點睇

OC包括Implicit cost 喎，你意思係？

OC= explicit + implicit?

依條明呀 岩岩都做錯左 淨係諗highest valued option forgone 然黎以為淨係B 但其他我就真係諗唔通 都似成日般龍門咁

好亂 都唔知佢個definition想點 又話highest valued option forgone但又要計埋俾左嘅錢

1st choice: A
2nd choice: B
3rd choice: C
咁嘅情況 你揀A嘅話 OC就會係B嘅value

但如果題目淨係比左一個choice(A)你
問你揀A嘅OC係乜
咁就會係揀A背後所出嘅錢 時間 同其他non-monetary cost

同樣道理
有個人用$30000買左樣野(當係A)個題
1st choice: A
2nd choice: B
但當B對買野個個人黎講嘅value係細過$30000嘅時候 就會變左：
1st choice: A
2nd choice: $30000 cash
3rd choice: B
咁OC就會係$30000
而當個$30000+value of B=value of A嘅時候
咁你揀A 已經係放棄左both B and $30000 cash
所以 當題目冇講到明value of B係幾多嘅時候 你唔知B定$30000 cash係個個人嘅2nd choice(highest-valued option forgone) 所以OC就會包埋個$30000

有個人own a house個題
paid a sum to buy a house已係sunk cost
唔計入OC
真正嘅OC係rental income forgone(自往緊冇得租比人收租)

有錯請指正

好清晰

其實opportunity cost = explicit cost + implicit cost?
Implicit cost 同 opportunity cost 係有啲混亂

大家點睇

own a house個part係咪解錯
opportunity cost 其實姐係你唔做一樣行為可以得到d咩
你唔own a house自然可以得到money returned from selling the house
OC of living in the house 先係monthly rental income forgone

sor 係我睇錯題目

所以上面位巴打嘅題目話有個人own a house
而佢bear an opportunity cost living in that house because he has paid a sum of money to buy the house係錯嘅
原因只係paid a sum of money只係sunk cost 前句岩後句錯
OC of living in that house先係rental income forgone
可以咁諗：買左間屋 自住vs出租 own the house vs resell

咁其實假設option A係去公園 （MB=$100)
Option B 去睇電影 (MB=$200, explicit cost=$80)
咁去睇電影嘅OC係咪$100，total cost先係$180？
去公園個OC係200定120？
呢個就係explicit定implicit個問題

咁其實假設option A係去公園 （MB=$100)
Option B 去睇電影 (MB=$200, explicit cost=$80)
咁去睇電影嘅OC係咪$100，total cost先係$180？
去公園個OC係200定120？
呢個就係explicit定implicit個問題

MB點解

咁其實假設option A係去公園 （MB=$100)
Option B 去睇電影 (MB=$200, explicit cost=$80)
咁去睇電影嘅OC係咪$100，total cost先係$180？
去公園個OC係200定120？
呢個就係explicit定implicit個問題

MB點解

Marginal benefit

咁其實假設option A係去公園 （MB=$100)
Option B 去睇電影 (MB=$200, explicit cost=$80)
咁去睇電影嘅OC係咪$100，total cost先係$180？
去公園個OC係200定120？
呢個就係explicit定implicit個問題

唔會會有cost唔係OC

咁其實假設option A係去公園 （MB=$100)
Option B 去睇電影 (MB=$200, explicit cost=$80)
咁去睇電影嘅OC係咪$100，total cost先係$180？
去公園個OC係200定120？
呢個就係explicit定implicit個問題

唔會會有cost唔係OC

？

其實有個位唔明好耐

點解當A係自己屋企唱歌嘅時候 B係佢隔離屋聽到佢嘅歌聲 而係A冇比/收B錢嘅情況下 如果B鍾意A嘅歌聲 就未必會有divergence between private and social benefits 但如果B唔鍾意A嘅歌聲 就一定會有divergence between private and social costs?

我自己嘅理解係 A唱歌都要用時間用力氣(private cost) 但佢都會換黎self-satisfaction(private benefit) 咁點解costs一定會有divergence而benefits冇

其實有個位唔明好耐

點解當A係自己屋企唱歌嘅時候 B係佢隔離屋聽到佢嘅歌聲 而係A冇比/收B錢嘅情況下 如果B鍾意A嘅歌聲 就未必會有divergence between private and social benefits 但如果B唔鍾意A嘅歌聲 就一定會有divergence between private and social costs?

我自己嘅理解係 A唱歌都要用時間用力氣(private cost) 但佢都會換黎self-satisfaction(private benefit) 咁點解costs一定會有divergence而benefits冇

係咁既咩

其實有個位唔明好耐

點解當A係自己屋企唱歌嘅時候 B係佢隔離屋聽到佢嘅歌聲 而係A冇比/收B錢嘅情況下 如果B鍾意A嘅歌聲 就未必會有divergence between private and social benefits 但如果B唔鍾意A嘅歌聲 就一定會有divergence between private and social costs?

我自己嘅理解係 A唱歌都要用時間用力氣(private cost) 但佢都會換黎self-satisfaction(private benefit) 咁點解costs一定會有divergence而benefits冇

係咁既咩

我都係岩岩做cliff yeung mock先知

其實有個位唔明好耐

點解當A係自己屋企唱歌嘅時候 B係佢隔離屋聽到佢嘅歌聲 而係A冇比/收B錢嘅情況下 如果B鍾意A嘅歌聲 就未必會有divergence between private and social benefits 但如果B唔鍾意A嘅歌聲 就一定會有divergence between private and social costs?

我自己嘅理解係 A唱歌都要用時間用力氣(private cost) 但佢都會換黎self-satisfaction(private benefit) 咁點解costs一定會有divergence而benefits冇

係咁既咩

我都係岩岩做cliff yeung mock先知

但之前都做過mock係咁出 個時已經

咁其實假設option A係去公園 （MB=$100)
Option B 去睇電影 (MB=$200, explicit cost=$80)
咁去睇電影嘅OC係咪$100，total cost先係$180？
去公園個OC係200定120？
呢個就係explicit定implicit個問題

其實有個位唔明好耐

點解當A係自己屋企唱歌嘅時候 B係佢隔離屋聽到佢嘅歌聲 而係A冇比/收B錢嘅情況下 如果B鍾意A嘅歌聲 就未必會有divergence between private and social benefits 但如果B唔鍾意A嘅歌聲 就一定會有divergence between private and social costs?

我自己嘅理解係 A唱歌都要用時間用力氣(private cost) 但佢都會換黎self-satisfaction(private benefit) 咁點解costs一定會有divergence而benefits冇

如果碰巧鋼琴家MPB = MPC果點係鄰居MB = 0
咁就無divergence between private benefit and social benefit

13年 econ3 14年retake 上到5 都係靠自己做pastpaper 零補習 當年我都係quit asso去retake 大家加油 仲有時間

其實有個位唔明好耐

點解當A係自己屋企唱歌嘅時候 B係佢隔離屋聽到佢嘅歌聲 而係A冇比/收B錢嘅情況下 如果B鍾意A嘅歌聲 就未必會有divergence between private and social benefits 但如果B唔鍾意A嘅歌聲 就一定會有divergence between private and social costs?

我自己嘅理解係 A唱歌都要用時間用力氣(private cost) 但佢都會換黎self-satisfaction(private benefit) 咁點解costs一定會有divergence而benefits冇

there may not be divergence between social and private benefit
係因為A sings at a output level where MPB+MEB=MSC
efficiency is implied

而當佢dislike既時候,佢唱半/一句,半/一秒都係dislike
唔存在有MPC+MEC=MSB既情況,所以必然有divergence

明白 唔該哂