IB MYP Individuals and Societies – Economic Agents, Measurements and Trends Study Guide

This study guide is for IB MYP Individuals and Societies and follows the International Baccalaureate Organization, Middle Years Programme Subject Brief – Individuals and societies, from 2014. It teaches two topics the brief lists for the individuals and societies on-screen examinations: economic agents and their role in the economy (the brief names consumers, producers, governments and banks) and measurements and trends. It suits MYP years 4 and 5; there is no SL/HL split.

MYP has no prescribed content list – schools design their own units. This page covers topics the IB’s brief lists, using standard economics. Your teacher will share the task-specific clarifications.

Use it with the revision notes for this unit and the practice questions for this unit. For the whole course, see the MYP Individuals and Societies hub and the printable checklist.

What this unit covers

Area	What you must be able to do	Criterion it mainly trains
Economic agents	Describe the roles and interests of households, firms, government and banks; use the circular flow	A
GDP and GDP per capita	Define GDP; calculate it from spending; convert nominal to real; judge it as a measure	A, B and D
Inflation	Define inflation; calculate a weighted price index and an inflation rate	A and B
Unemployment	Define it; calculate the unemployment rate; name the types	A and B
Human Development Index	Name its three dimensions; combine three indices; compare with GDP per capita	A and D
Trends in data	Describe and explain trends, with figures	B, C and D

The brief names four equally weighted criteria – A Knowing and understanding, B Investigating, C Communicating, D Thinking critically – each with eight achievement levels (1–8) in four bands. For how the tasks work, see how MYP Individuals and Societies is assessed.

The brief’s key concept systems fits this unit (an economy is a set of connected agents), as does change (trends) and the global context fairness and development.

Economic agents

An economic agent is any person or organisation that makes economic decisions.

Agent	Main role	Main interest
Households (consumers)	Buy goods and services; supply labour and other factors of production; save	The most satisfaction from limited income
Firms (producers)	Combine land, labour, capital and enterprise to make goods and services; employ people; invest	Profit; also growth and survival
Government	Collects taxes; provides public services (roads, defence, schools); pays benefits; makes laws and regulations	Well-being of citizens, stable prices, jobs, growth; also re-election
Banks	Take deposits from savers; lend to households and firms; handle payments	Profit from the gap between the interest they charge borrowers and pay savers

A central bank is the bank of the government and of other banks. It usually sets the main interest rate, which affects borrowing and spending.

Conflicts of interest are useful in extended writing: firms want lower wages and higher prices; workers and consumers want the opposite; government wants tax revenue that households and firms would rather keep.

The circular flow of income

Households supply factors of production to firms, which pay rent (land), wages (labour), interest (capital) and profit (enterprise). Households spend that income on firms’ output, so money flows in a circle. Real economies also have:

• Leakages (withdrawals) take money out of the circle: saving, taxes, imports.
• Injections add money in: investment by firms, government spending, exports.

If injections exceed leakages, the flow of income grows. Banks turn households’ saving into loans for firms’ investment.

Gross domestic product (GDP)

GDP is the total value of all final goods and services produced within a country in a year. “Final” avoids double counting: count the bread, not also the flour in it.

GDP can be measured by output, by income or by expenditure; all three should give the same total:

GDP = C + I + G + (X − M)
C = consumer spending      I = investment by firms
G = government spending    X = exports     M = imports

GDP per capita = GDP ÷ population, for comparing countries of different sizes.

Worked example: Aldmere (fictional data)

In one year Aldmere had C = 620, I = 150, G = 210, X = 280 and M = 300 (all in billions of crowns, Aldmere’s fictional currency). The population was 32 million.

GDP = 620 + 150 + 210 + (280 − 300)
    = 980 − 20 = 960 billion crowns
GDP per capita = 960,000,000,000 ÷ 32,000,000 = 30,000 crowns

Negative net exports (a trade deficit) reduce GDP.

Nominal and real GDP

Nominal GDP uses each year’s prices, so it rises when prices rise. Real GDP removes inflation:

real GDP = nominal GDP ÷ price index × 100

The next year, Aldmere’s nominal GDP was 1,040 billion crowns and the price index was 104 (base year = 100). The population grew to 32.5 million.

nominal growth = (1,040 − 960) ÷ 960 × 100 = 8.3%
real GDP = 1,040 ÷ 104 × 100 = 1,000 billion crowns
real growth = (1,000 − 960) ÷ 960 × 100 = 4.2%
real GDP per capita = 1,000,000,000,000 ÷ 32,500,000 = 30,769 crowns
growth in real GDP per capita = (30,769 − 30,000) ÷ 30,000 × 100 = 2.6%

About half of the nominal growth was only higher prices, and output per person grew more slowly still because the population grew. Economic growth means a rise in real GDP.

What GDP per capita does not show

• Distribution: an average hides inequality.
• Informal economy and unpaid work: street trading, subsistence farming and caring are often missing.
• Quality of life: leisure, health, freedom and safety are not measured.
• Environment: pollution is not subtracted; clean-up spending even adds to GDP.
• Prices differ between countries, so economists adjust for purchasing power parity (PPP) – what money actually buys in each country.

Inflation

Inflation is a sustained rise in the general level of prices. It means each unit of money buys less. Deflation is a sustained fall in the general price level. Disinflation is a fall in the rate of inflation – prices are still rising, just more slowly.

Inflation is usually measured with a consumer price index (CPI): the price of a “basket” of goods and services a typical household buys, each with a weight showing its share of spending. The base year = 100.

inflation rate = (CPI this year − CPI last year) ÷ CPI last year × 100

Worked example: a weighted price index

Category	Weight	Price change over the year
Food	30	+6%
Housing	25	+4%
Transport	20	−2%
Other	25	+3%

weighted change = (30×6 + 25×4 + 20×(−2) + 25×3) ÷ 100
                = (180 + 100 − 40 + 75) ÷ 100 = 3.15%
CPI rises from 100 to 103.15 (103.2 to 1 d.p.)

A simple average of the four changes (2.75%) is wrong: households spend more on food than on transport.

Who is affected: savers and people on fixed incomes lose when inflation beats their interest rate or pay rise; borrowers can gain. If wages rise 2% while prices rise 3.15%, real wages fall by about 1.1%.

Unemployment

A person is unemployed if they are of working age, without a job, available for work and actively looking. The labour force = employed + unemployed. People who are neither (students, retired people, full-time carers) are economically inactive.

unemployment rate = unemployed ÷ labour force × 100

Worked example (fictional data)

Aldmere has 21.0 million people of working age: 13.8 million employed and 1.2 million unemployed.

labour force = 13.8 + 1.2 = 15.0 million
unemployment rate = 1.2 ÷ 15.0 × 100 = 8.0%
economically inactive = 21.0 − 15.0 = 6.0 million

Do not divide by 21.0 million.

Percentage points. If the rate falls from 8.0% to 6.0%, it has fallen by 2 percentage points, which is a 25% fall in the rate. Keep the two ideas apart.

Type	Cause	Example
Frictional	Short gap while moving between jobs	A graduate searching for a first job
Seasonal	Demand changes with the seasons	A beach lifeguard in winter
Structural	Industries decline; skills no longer match jobs	Miners after coal mines close
Cyclical (demand-deficient)	Low spending in a recession	Factory workers laid off when sales fall

Official figures miss people who have stopped looking and underemployment (wanting more hours).

The Human Development Index (HDI)

The HDI was first published by the United Nations Development Programme (UNDP) in 1990. It measures development more broadly than income, using three dimensions:

Dimension	Indicator
A long and healthy life	Life expectancy at birth
Knowledge	Mean years of schooling (adults aged 25+) and expected years of schooling (children starting school)
A decent standard of living	Gross national income (GNI) per capita, adjusted for PPP

Each indicator becomes a 0–1 index using “goalposts”: life expectancy 20 to 85 years; expected schooling 0 to 18 years; mean schooling 0 to 15 years; GNI per capita 100 to 75,000 PPP dollars, using natural logarithms. The HDI is the geometric mean of the three dimension indices (multiply them and take the cube root). The UNDP groups countries as very high (0.800 and above), high (0.700–0.799), medium (0.550–0.699) and low (below 0.550).

Worked example: Aldmere (fictional data)

Life expectancy 77.0 years; expected schooling 15.0 years; mean schooling 10.5 years; GNI per capita 20,000 PPP dollars.

health index    = (77.0 − 20) ÷ (85 − 20) = 57 ÷ 65 = 0.877
education index = (15.0 ÷ 18 + 10.5 ÷ 15) ÷ 2 = (0.833 + 0.700) ÷ 2 = 0.767
income index    = (ln 20,000 − ln 100) ÷ (ln 75,000 − ln 100)
                = 5.298 ÷ 6.620 = 0.800
HDI = (0.877 × 0.767 × 0.800)^(1/3) = 0.813   → very high

The logarithm means each extra dollar counts for less as income rises. The HDI still ignores inequality, freedom and the environment: better than GDP per capita for comparing development, not perfect.

Reading trends in tables and graphs

Brenvale (fictional data)

Year	Real GDP growth (%)	Inflation (%)	Unemployment (%)
2020	−3.2	1.1	7.9
2021	4.1	2.4	7.1
2022	3.0	6.8	6.0
2023	2.2	5.1	5.4
2024	1.8	3.2	5.2
2025	2.5	2.6	5.5

A strong description follows four steps:

1. Overall trend, with start and end figures: unemployment fell from 7.9% in 2020 to 5.5% in 2025.
2. Rate of change: the fall was fastest in 2020–2022 (1.9 percentage points) and then slowed.
3. Anomalies: a recession in 2020 (the only negative growth); an inflation peak of 6.8% in 2022; unemployment rose slightly in 2025.
4. Links, carefully: unemployment fell as output recovered. Say “is consistent with”, not “proves” – correlation is not cause.

Two traps: falling inflation (6.8% to 2.6%) does not mean prices fell – they rose every year; and slower growth (1.8% in 2024) still means GDP grew. On graphs, check whether the vertical axis starts at zero, and whether data are totals or per capita, nominal or real, levels or rates of change.

Common errors

• Writing GDP = C + I + G + X + M. Imports are subtracted.
• Saying “prices fell” when inflation fell from 5% to 3%.
• Dividing unemployed by all people of working age instead of the labour force.
• Confusing a 2 percentage point fall with a 2% fall.
• Adding the three HDI indices and dividing by 3 (the arithmetic mean) instead of the geometric mean.

Next steps

Test yourself with the revision notes and practice questions. See also the subject guide, the four criteria in practice, the disciplines and, for population data, demographics and human movements.

Official syllabus

This page is aligned to the International Baccalaureate Organization, Middle Years Programme Subject Brief – Individuals and societies, from 2014. The brief lists “economic agents and their interests and role in the economy: consumers, producers, governments, banks” and “measurements and trends” among the topics explored in the individuals and societies on-screen examinations. The full MYP individuals and societies guide is available to schools through the IB.