Jargon Buster
Percentage change
- What does this mean?
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A quantified alteration in something expressed as a percentage.
The terms percentage and percentage change are sometimes confused with each other. If the percentage of people attracted from a given area rises from 10% to become 12%, it has risen by 2 units or 2 percentage points. But the percentage increase (or change) undergone by the original 10% is 20% (i.e. the underlying ‘unit’ change is 12 - 10 = 2, and 2 out of 10 times 100 = 2 ÷ 10 × 100 = 20%).
Hence care should be taken to use the most appropriate means of calculating and expressing a change using percentages. The shift from 10% to 12% could be expressed as a rise of 2 percentage points, or as a 20% increase. However, it is inadvisable to combine the two different ways of saying this. As The Guardian Stylebook emphasizes, ‘an increase from 3% to 5% is a 2 percentage point increase, not a 2% increase.’
