EC212 · LESSON 02 / 08

2. What GDP counts

Paddy is sold to a mill and rice is sold to a household. Adding every sale would count the same production more than once.

Understand

What is this lesson explaining?

GDP measures final goods and services produced inside a country during a period. Location of production matters, not the nationality of owners. Used goods are not new output, but newly provided brokerage services count.

The expenditure approach adds C consumption, I real investment including inventories, G government purchases, and X − IM net exports. Buying shares transfers an asset; it is not GDP investment.

KEY MODEL

Y = C + I + G + X - IM

YGDP in the same periodC, I, GConsumption, real investment, and government purchasesX, IMExports and imports of goods and services

See it on a graph

The graph is right here

Read the axes and original point first. Then change one value at a time and watch the curve or point move.

GDP = C + I + G + NXCount final goods and services produced domestically

CConsumptionIInvestmentGGovernmentNXNet exports

Quick check

NO TYPING

Government pays transfers of 50 and buys new services for 30. What enters G directly?

Takeaway

Remember these two ideas

✓

Suppose C = 500, I = 120, G = 150, X = 90, and IM = 110. GDP is 750 monetary units.

Common mix-upHigher imports do not mechanically lower GDP: if an imported purchase raises both C and IM by 20, the direct accounting effects cancel.

Assumptions and sources

Values use consistent units and periods. This expenditure equation is an accounting identity.

EC212 tutoring outline: chapters 1–8 (local course outline)
Mankiw, Macroeconomics, 8th edition, chapter 2, pp. 21–28