The basic reproductive rate or the intrinsic rate of reproduction is the number of secondary infections caused by a single infectious case. This metric is useful because it helps determine whether or not an infectious disease will spread through a population. If this number is greater than one, on the average, a disease will take off. If this number is less than one, on the average, a disease will eventually fade from a population.

This statistic is often referred to by the name R₀. It was originally used by George MacDonald in 1952, who constructed population models of malaria.

See also

• Theoretical ecology.
• Branching process.