This is a Lexis plot. It shows how American mortality rates—the proportion of people who die at every age each year—changed over time. Researchers use these rates to calculate life expectancy.
A study recently published in PNAS analysed this chart and warned of “an unprecedented longer-run stagnation, or even sustained decline” in American life expectancy.
Here is how to read it.
The chart is made up of a grid of squares. Bright green squares reflect decreases in mortality, or fewer people dying. Dark blue ones correspond to more deaths.
Each column represents a year. This column of green squares means that fewer people of all ages died in 1997 than in 1996. When mortality rates fall across age groups, as they did that year, life expectancy rises.
