GDP & the Expenditure Approach
Separate consumption, fixed investment, inventory change, government and net exports; understand domestic production and inventories across years.
Question, try, then observe
What did you just see?
A factory produces USD 1,000 of new goods this year but sells only USD 600. Current production is still USD 1,000: consumption 600 plus inventory accumulation 400. Selling the remaining 400 next year adds consumption 400 and subtracts inventory 400, avoiding a second count of last year's output.
Territory, time and final production
Domestic refers to resident producing units and economic territory, not workers' passports. A period separates flows from stocks: is not the nation's total wealth. Final production avoids adding flour and bread sale values twice. If flour contributes value added of 40 and the baker adds 60, a final loaf worth 100 contributes 100, whether measured as final expenditure or summed value added.
Inventories across years without double counting
Closing inventory equals opening inventory plus production minus sales; current inventory investment is closing minus opening stock. In year one, make 10 items and sell 6 at USD 100: consumption 600 and inventory accumulation 400. In year two, produce none and sell 4: consumption 400 and inventory decumulation 400, so new production of this good is zero. Change sales quantities and check the identity, but sales cannot exceed available stock.
The simple model versus official inventory accounts
This two-year model uses one domestically produced good, a constant unit price, no intermediate inputs and no additional distribution services. Holding gains from price changes are not new production; official accounts require appropriate inventory valuation adjustments. Imported inventories require matching import deductions; new domestic transport or brokerage can add value separately. Do not apply this simple sales/inventory example to complex inventories without those adjustments.
Foreign workers, foreign owners and overseas subsidiaries
Value added by foreign workers for a Taiwan-resident producing unit enters Taiwan's , as does production by a foreign-owned resident unit in Taiwan. A Taiwan company's resident overseas subsidiary contributes to its host economy's GDP, not directly Taiwan's GDP. Short-term cross-border services and nonresident units require national-accounts residence and transaction rules; physical presence alone is insufficient.
GDP, GNI and nominal versus real
follows domestic production; GNI follows primary income received by residents: GNI=GDP+net primary income from abroad. Income such as overseas-subsidiary dividends can affect resident income, but total overseas output is not simply added to home GNI. Nominal GDP uses current prices; real GDP adjusts for price changes to compare output volumes. Official chained-volume components need not be additive; this calculator decomposes expenditure amounts on one consistent price basis.
A transaction is not necessarily new production
Reselling used goods or existing homes does not reproduce their original value, but current brokerage services can count; new homes are fixed investment. Stock and bond trades transfer financial assets, while related service fees may be production. Government transfers are not direct purchases of output; procurement counts according to its goods and services. Imported goods are not domestic output, though domestic added services can count. Unpaid own-household services generally lie outside ; exceptions such as imputed owner-occupied rent mean not all nonmarket activity is excluded.
Another example
- Use billion USD with one period and price basis; enter 600, 100, −20, 200, 150 and 130.
- Combine fixed investment with inventories for I=80, and exports minus imports for net exports=20.
- GDP=600+80+200+20=900. Imports are subtracted to remove foreign production, not to imply imports necessarily harm an economy.
Show formal definition and formula
GDP is the value of final goods and services produced during a period by resident producing units in an economic territory, also measurable through value added. The expenditure approach matches that current production with consumption, investment, government spending and net exports.
GDP expenditure identity
Fixed investment and inventory investment
Fixed-price teaching inventory identity
GDP is the value of final goods and services produced during a period by resident producing units in an economic territory, also measurable through value added. The expenditure approach matches that current production with consumption, investment, government spending and net exports.
- C
- Consumption
- Ifixed
- Private fixed investment
- ΔInventory
- Inventory investment, can be negative
- G
- Government consumption and investment
- X
- Exports
- M
- Imports
- Sstart
- Opening inventory units
- Send
- Closing inventory units
- Q
- Current production units
- V
- Current sales units
- Units
- Amounts use billion TWD with one period and price basis; inventory change can be negative. The teaching stock example uses units and a fixed NT$100 per item, separately from aggregate amounts.
Common mistakes
GDP is not assigned by worker nationality or recounted whenever a good changes hands. Financial and government payments do not all represent production. Inventory stocks differ from inventory investment; import deductions remove foreign output.
Frequently asked questions
Can military procurement enter GDP?
It can enter government consumption or investment under national-accounts rules, a different question from active-duty military exclusion from civilian labor surveys.
You can now explore…
- Understand expenditure GDP and inventory accounting across years
- Classify production by resident unit and production period
Term reference1 terms
Open a term when you need a reminder. Underlined words in the article work too.