Lesson preview · Planning an investigation
Planning an economics investigation
~8 min · Free to read
Imagine your teacher sets an economics project, and you pick “Is fast food bad for the economy?” Three weeks later, you have pages of notes and no answer. No data could settle a question that big.
Now try “How did the canteen’s March price rise change how many sandwiches students bought each week?” You can count sandwiches and compare weeks, so you can answer it.
Key Term
A question you can answer
An investigation answers an economic question with evidence. A good question is narrow: one market or policy, one place, one stretch of time. It is also answerable with data: you can name the figures that would settle it.
- Too broad: “How does inflation affect people?”
- Narrow: “Did bus fares in my city rise faster than prices in general from 2020 to 2025?”
A “should” question, such as “Should buses be free?”, is normative: it rests on values, so data alone can’t settle it. Save the “should” for your judgement at the end.
Key Term
Choose your model first
A model is a simplified picture of how one part of the economy works, such as demand and supply. Pick it before you collect any data. It tells you what to measure, and what else to check.
Key Term
Primary and secondary data
Primary data is data you collect yourself, such as a survey of 50 students or prices from five shops. It fits your question exactly, but samples are usually small.
Secondary data is data someone else collected, such as figures from a statistics agency, a central bank or a firm. It covers more people, but may not measure exactly what you need.
For every source, note who published it, its title, date and link, and when you used it. This record, a citation, lets a reader check your figures.
Evaluation means weighing your own evidence: what makes it strong, and what limits it. Then give a judgement: your answer, and how sure you can be.
Worked Example
Imagine Amira’s school canteen raises its sandwich price from 2 dollars to 2.50 dollars at the start of March. Her project has a 2,000-word limit. Plan her investigation.
Trap · Common Misconception
"It happened after the change, so the change caused it"
Imagine a city taxes sugary drinks from January, and by March sales are down 8 percent. Maybe the tax worked. But a national TV health campaign began the same month. The tax and the fall in sales go together: two things moving together is a correlation. One thing making the other happen is causation. To get closer to cause, hold all else equal with a comparison group: a similar city that saw the campaign but had no tax.
Tip
Your planning checklist
Before you collect data
- Question: narrow, answerable, with a place and a time.
- Model: named, with the other factors it says to check.
- Data: primary, secondary or both, with every source cited.
- Words: a word plan within any limit, with real space for the evaluation.
Before you hand it in
- Analysis: calculations shown and diagrams labelled.
- Cause: other explanations ruled out, or named as a limitation.
- Evaluation: strengths, limitations and a judgement.
Trap · Warning
Your work, your answer
This lesson gives you a structure, not an answer: the question, the data and the judgement must be yours. Before you start, check your school’s rules on help from other people and AI tools.
Check yourself · no marks
Is this a good investigation question? “Why are house prices so high?” If not, rewrite it so you could answer it with data.
Commit to one first. Guessing and being wrong beats reading the answer cold.
Practice · 1 / 6
Which of these is the best question for an economics investigation?
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