How to use scatter plots to explore the relationship between two indicators, summarize it with a regression line, and highlight individual countries.
Scatter plots show relationships between two indicators.
Each dot represents a country, positioned according to its value on each axis.
In this example, the horizontal axis shows GNI per capita (shown on a logarithmic scale), and the vertical axis shows the fertility rate. The downward pattern of the scatter plot suggests that countries with higher income tend to have lower fertility rates.
Add a regression line to summarize the relationship.
The fitted line summarizes the overall relationship between the two indicators. In this example, the line slopes downward, indicating that countries with higher income tend to have lower fertility rates.
The individual dots remain important. Countries do not all fall on the line, revealing variation around the overall trend and highlighting countries that differ from the expected pattern.
Highlighted countries provide examples of variation around the overall pattern.
In this example, Niger is highlighted in the upper left, with low income and high fertility, while Singapore is highlighted in the lower right, with high income and low fertility. Israel sits above the regression line, illustrating that some countries differ from the overall trend.
Highlighting countries helps you move beyond the overall pattern to explore how individual countries compare.