A comparison of two periods shows a difference, not the reason for it. Before you call the difference good or bad, check for season, one-off items, size changes and different definitions.
This lesson is part of financial statements and interpretation. It leads into interpreting performance beyond one ratio.
What can make a two-period comparison misleading?
Four things are worth checking in every case.
- Season: one period may include a festival or a school holiday.
- One-off items: a large sale or an unusual cost that will not repeat.
- Size: the business may have grown or shrunk between periods.
- Definitions: the two periods may count items differently.
If any one applies, the comparison needs a warning.
Worked example: a festival month
A fictional stall, Kuih Raya, sells cookies. In an ordinary month its sales are RM12 000 and its net profit is RM1 800, a net margin of 15%. In the festival month, sales are RM30 000 and net profit is RM6 000, a net margin of 20%.
Comparison. Profit rose by RM4 200, from RM1 800 to RM6 000. The margin rose from 15% to 20%.
What the comparison cannot show. The festival month is a season in which customers buy gifts. The rise may come from the season and not from better management. One festival month cannot show what happens in an ordinary month next time.
Qualified conclusion. The figures suggest that the stall earns more in the festival month. More months, including the next ordinary month, are needed to confirm whether the stall has really improved.
Extra information that would help. Sales and profit for the same months last year, and a record of one-off costs such as temporary staff.
The conclusion says what the figures support and what they do not.
The mistake that costs marks
The common slip is concluding “the stall is now much more profitable” from one festival month.
| Step | Wrong | Right |
|---|---|---|
| Figures | profit rose from RM1 800 to RM6 000 | the same |
| Conclusion | the stall is much more profitable | the festival month suggests higher profit |
| Context | not mentioned | festival season may explain the rise |
| Next step | none | compare with the same months last year |
A qualified conclusion is not a weaker answer. It is an accurate one.
Check yourself
A shop’s profit in December was RM8 000, compared with RM3 000 in November. Its owner says the shop has “doubled its efficiency”. Write a qualified comment.
Answer
Profit rose by RM5 000, which is more than double, but December may include a school holiday or year-end shopping, so the rise may come from the season.
A qualified comment: “The figures suggest December was stronger, but the season may explain this. Comparing with December last year, and with January, would show whether efficiency improved.”
What to study next
Go on to interpreting performance beyond one ratio, which covers sales, profit and cash together. Then test yourself with the practice set.
The business case answer planner can hold space for a limitation line in each answer. For a teacher to read your conclusions with you, see online one-to-one Business tuition.