tool 01 · rule of 70
How long until the economy doubles?
Slide a growth rate. The rule of 70 estimates how many years it takes for the economy to double in size, and shows how much it grows in a century.
2.0% / year
drag the slider, or click the typical values below.
Doubling time
35 years
at 2.0%, the economy doubles roughly every 35 years.
In 100 years, the economy grows by a factor of
7.2×
$60,000 per person becomes about $432,000.
In 200 years
52×
Quick check
Move the slider to 7%, then look at the doubling time. Roughly how long does a 7-percent-per-year economy take to double?
Defined on: the slider readout above.tool 02 · country growth comparison
Pick two countries. Watch the divergence.
Real GDP per capita for a handful of large or instructive economies, 1820 to 2018, in inflation-adjusted dollars. Estimates from the Maddison Project; the data is approximate (especially pre-1900) and is shown on a log scale so curves of different sizes are visually comparable.
Quick check
Pick South Korea and Argentina, then set the starting year to 1960. In 1960 both countries had roughly similar real GDP per capita (around $1,500 to $1,700). By 2018, South Korea is about 38× richer; Argentina is about 13×. Which of the following best explains a divergence like this?
Defined on: the chart and summary above.