GDP三種算法 - 經濟

※ 引述《chris1 (小刀)》之銘言：
: on an island in the indian ocean, people grow coconuts, and
: import fertilizers. A merchant manages all the farms. This year, they
: used $15,000 fertilizers(imported that year) and grew $75,000 coconuts.
: The merchant pays $30,000 to the landlord. Since last year was a year of
: good harvest, the merchant of the village kept $5,000 coconuts as inventory.
: This year, the merchant ends up selling the coconuts in stock for $15,000.
: Therefore, the total value of coconuts consumed is $90,000 this year. What
: was the island's GDP for this year? Please come up with the result by
: (i) the product approach
: (ii) the expenditure approach
: (iii) income approach
: 搞不懂的點是，到底是不是消費了90000呢? 但今年明明只收成了75000不是嗎...
: 題目的意思是還有加去年的5000嗎? 但加起來也才80000而已...搞不懂怎麼來的
: 九萬，而且，那個15000，是賣剩下來，當今年的存貨嗎？
: 我的想法是，假如九萬是錯的，那
: (i) 75000，因今年度就只生產出這75000的coconuts，要再扣進口15000嗎?
: (ii) C=75000+5000-15000=65000 I=15000-5000=10000 M=15000
: GDP=65000+10000-15000=60000
: (iii) 30000(farmers)+30000(landlord)=60000
: 不知道這樣對不對呢？請幫幫忙，感恩

以下用詞，很多和教科書上的不太一樣

(i) GDP = GVA (tax and subsidy is not mentioned)

GVA = Σoutput - Σintermediate consumption
= total output of coconut production and rental activities
minus cost of fertilizers and rent
= (75,000 + 30,000) - (15,000 + 30,000)
= 60,000

Therefore, GDP = GVA = 60,000


(ii) GDP = Final consumption expenditure + GCF + net export
= the total value of coconuts consumed (incl. export)
plus changes in inventories
minus import
(GFCF is not mentioned)
= 90,000 + (X-15,000) - 15,000
= 90,000 + (-15,000) - 15,000
(X = output of coconut production
minus (total value of coconuts consumed
minus value of coconuts sold in stock)
= 75,000 - (90,000 - 15,000) = 0 )
= 60,000

消費的九萬，包括當年產出的，與之前的存貨
之前存貨的價值有多少，題目並沒有交待
我們只知道前一年存貨增加的價值為五千

題目先給定售出存貨的價值為一萬五，不管消費給多少，GDP 仍然是六萬
(a) 如果消費等於九萬，表示當年生產的椰子全部賣出，
即上述 X = 0，存貨變化為 -15,000
GDP = 90,000 + (-15,000) - 15,000 = 60,000
(b) 如果消費小於九萬，表示當年生產的椰子沒有賣完而成為存貨，
即上述 X > 0，存貨變化為 X-15,000，消費為 90,000-X，
GDP = (90,000-X) + (X-15,000) - 15,000 = 60,000
(c) 如果消費大於九萬，表示當年生產的椰子不僅賣完，
商人還進口其他地方生產的椰子，即上述 X 屬於進口的項目，
GDP = (90,000+X) + (-15,000) - (15,000+|X|) = 60,000


(iii) GDP = gross operating surplus and mixed income
plus compensation of employees
(tax and subsidy is not mentioned)
= GVA - compensation of employees
plus compensation of employees
= GVA = 60,000

地主的租金收入為 30,000
商人與農夫的收入總和為毛利 = 銷售 - 銷貨成本(肥料 + 租金 - 存貨變化)
= 90,000 - (15,000 + 30,000 - (-15,000))
= 30,000

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