IB Economics HLTopic 4 — The Global EconomyPaper 1, 2 & 3Diagram skill~11 min read
Poverty Traps
A poverty trap is not a story about laziness or bad luck. It is a circle in which being poor is itself the reason you stay poor, and the diagram on this page is one of the most useful things in the whole development unit.
📚 What you need to know
A poverty trap is a self-reinforcing cycle that keeps incomes low.
Low wages sit at the centre, where two loops meet.
The growth loop: low wages, low saving, low investment, low growth, back to low wages.
The development loop: low wages, poor education and health, low human capital, low productivity, back to low wages.
The cycle is stable, so it usually needs an outside push to break.
Every development policy can be described as an attempt to cut into this circle somewhere.
The cycle
Read it as two rings joined at the middle. Both start and end at low wages, which is why the trap holds even when only one of the two loops is working.
Draw this from memory. If a question asks about barriers to development, sketching the trap and marking where a policy cuts in is the fastest route to a strong answer.
Walking round the two loops
Loop
Stage
Why it follows from the last one
Growth
Low saving
When wages barely cover food, rent and fuel, there is nothing left to put aside
Growth
Low investment
Banks lend out what savers deposit. Few deposits means little credit for firms
Growth
Low economic growth
Without new machinery, tools and premises, productive capacity barely expands
Growth
Back to low wages
A stagnant economy creates few jobs, so there is no competition to bid wages up
Development
Poor education and health
Both cost money directly or indirectly, and low-income households cannot pay
Development
Low human capital
Fewer skills and more illness mean a workforce that can do less
Development
Low productivity
Output per worker stays low, so each worker generates little value
Development
Back to low wages
Firms pay according to what a worker produces, so low productivity means low pay
The indirect cost of schooling is the part most students miss. Even where fees are zero, sending a child to school means losing the income that child could have earned. For a household on the edge, that opportunity cost is the binding constraint — which is why cash transfers conditional on attendance work so well.
Why it does not fix itself
A trap is stable. Small improvements get absorbed: a slightly better harvest raises consumption rather than saving, because consumption was below what the household needed in the first place. That is why economists talk about needing a big push — an intervention large enough to lift the economy past the point where the loops start working in reverse.
The threshold idea. Below a certain income, extra money goes on survival. Above it, some goes into saving and schooling, and the loops begin to turn the other way. Development policy is largely about getting households over that line and keeping them there.
Where to cut in
This is the single most transferable habit in the development unit. Whatever policy the question names, say which arrow it attacks and trace the consequences round the loop.
Worked examples
WORKED EXAMPLE 1
Using a poverty trap diagram, explain how low incomes lead to low incomes. [6]
Step 1: draw and label
Two loops meeting at low wages, with arrows showing the direction of causation.
Step 2: trace the growth loop
Low wages leave no surplus to save, so banks have few deposits, so firms cannot borrow to invest, so productive capacity and growth stay low, so few jobs are created and wages stay low.
Step 3: trace the development loop
Low wages mean households cannot afford schooling or healthcare, so human capital stays low, so output per worker stays low, so firms cannot pay more.
Step 4: state the conclusion
Each loop returns to its starting point, so the outcome is self-reinforcing rather than self-correcting.
Poverty persists because poverty removes the means of escaping it
WORKED EXAMPLE 2
A government introduces free school meals for primary pupils. Explain how this could break the poverty trap. [4]
Step 1: where it enters
At the education and health stage of the development loop.
Step 2: the immediate effect
Attendance rises because the meal lowers the cost of sending a child, and better nutrition improves learning and reduces illness.
Step 3: round the loop
Human capital rises, so productivity rises, so wages rise.
Step 4: the second loop
Higher wages allow some saving, which raises investment and growth, so the growth loop starts turning the right way too.
One intervention at one point can reverse both loops, but only if sustained long enoughthe “only if sustained” clause is your evaluation — human capital takes a generation
💡 Exam tip
Learn to draw the trap quickly with arrows in the right direction. Undirected arrows lose marks.
Label the centre low wages and say the two loops meet there.
Explain why each stage follows, rather than listing the boxes.
For any policy question, name the entry point and trace the consequences round.
Add a time dimension in evaluation: the growth loop responds in years, the development loop in decades.
⚠ Common mix-up
A poverty trap is not the same as poverty. The trap is the mechanism that keeps it going.
It is not about individual choices. Every step is a reasonable response to a bad situation.
Do not mix up saving and investment. Saving is income not spent; investment is spending on capital goods.
Growth alone does not break it. If the gains go to a small group, the loops keep turning for everyone else.
Do not draw one big circle. The examiner wants two loops joined at low wages.
Up next: Economic, Political and Social Barriers — the specific obstacles that hold the trap in place, and how to pick the ones that matter in a data-response extract.
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