Percent Versus Percentage Points
Introduction
Welcome back to Percentages in News and Statistics! This is lesson five of six, so we are nearly at the finish line. In earlier lessons, we learned how to calculate percent changes, identify the group behind a reported percentage, estimate real counts from those percentages, and compare percentages across groups of different sizes. Now we tackle one of the most common sources of confusion in news and data reporting: the difference between a change measured in percentage points and a relative percent change. These two phrases sound almost identical, but they describe very different things. Mastering this distinction will sharpen the way we read headlines, polls, and statistical claims.
Two Ways to Talk About the Same Shift
Consider a simple scenario: a city's recycling rate moves from 20% to 25%. How should we describe that change? One natural answer is "it went up by 5." Another perfectly valid answer is "it went up by 25%." Both statements can be correct, yet they measure different things.
The first description focuses on the gap between the two percentages — a straightforward subtraction. The second describes how large that gap is compared to where we started — a proportional comparison. This entire lesson is about learning to tell these two descriptions apart and recognizing which one a news report is actually using.
Percentage Points: The Simple Difference
When we subtract one percentage from another, the result is measured in percentage points (often abbreviated pp). It is the straightforward arithmetic difference between two percentage values:
In our recycling example, the rate went from 20% to 25%, so the change is percentage points. Notice that we say "5 percentage points," not "5 percent." The phrasing "percentage points" signals that we are simply measuring the distance between two percentages on the 0-to-100 scale, with no further calculation involved.
Relative Percent Change: The Proportional Shift
As we covered in the first lesson of this course, percent change tells us how large a change is relative to the starting value. The formula works the same way even when the values being compared are themselves percentages:
Returning to our recycling example, the starting value is 20% and the difference is 5 percentage points:
So the recycling rate increased by 25% relative to where it started. That is a very different number from the 5 percentage-point change, even though both describe the exact same shift from 20% to 25%.
A quick visual makes the distinction easier to see:
