Common O Level Economics mistakes

These three mistakes come up in almost every set of O Level scripts I mark. None of them is about knowing less economics. They are habits, and habits can be fixed in an afternoon.

1. Diagrams with no labels

A diagram with unlabelled axes earns very little, however neat it is. The examiner cannot give you a mark for a picture that could be about anything.

Every time you draw a demand and supply diagram, do these five things:

• Label the vertical axis Price, or P.
• Label the horizontal axis Quantity, or Q.
• Label every curve: D, S, and D1, D2 or S1, S2 when one of them moves.
• Mark the equilibrium price and quantity with dotted lines to the axes.
• Put an arrow on the curve that moved, so the direction is obvious.

Then write one sentence that points at the diagram. As the diagram shows, supply shifts from S1 to S2, so the price falls from P1 to P2. That sentence turns a drawing into an argument.

The same applies to a production possibility curve. Label both axes with the two goods, and label the curve itself.

2. Describing when the question says explain

Describe and explain are different command words and they are worth different marks.

Describe asks you to state the points of a topic and give the main features. Explain asks you to give reasons, make the links clear, and say why or how.

Here is the difference on the same question about a fall in the exchange rate:

Describing: exports rise and imports fall.

Explaining: a lower exchange rate means foreign buyers need less of their own currency to buy the same goods, so the country's exports look cheaper abroad, so foreign demand for them rises.

The test is simple. Read your sentence back and ask whether it contains the word because, or so, or a reason of any kind. If it does not, you have described.

Build the habit of writing in steps. A causes B, which causes C, which causes D. Two or three steps is usually enough at O Level.

3. Definitions that repeat the word

A definition that uses the word it is defining scores nothing, because it has not told the examiner anything.

Weak: inflation is when there is inflation in prices.

Weak: opportunity cost is the cost of the opportunity.

Good: inflation is a sustained rise in the general price level over a period of time.

Good: opportunity cost is the next best alternative given up when a choice is made.

Learn the short, exact wording for the terms that come up most: scarcity, opportunity cost, demand, supply, equilibrium, inflation, unemployment, economic growth, the balance of payments. One clean sentence each. Write them out from memory, then check them, then write them again the next day.

The command word Define means give precise meaning, so precise is what you are being marked on. Keep it to one sentence and resist the urge to add an example unless you are asked for one.

A quick self check

Before you hand in a past paper, spend two minutes on this:

• Does every diagram have both axes and every curve labelled?
• Does every explain answer contain a because or a so?
• Does any definition repeat the word it defines?
• Did you use the data in Section A, or did you answer from memory?

Doing this on your own work is worth more than reading another chapter, because it fixes the marks you are actually losing.