Generation Time

Generation time is a quantity used in population biology and demography to reflect the relative size of intervals of offspring production. Generation time usually expresses the average age of breeding females within a population. In epidemiology, it is defined as the interval of time between receipt of infection by a host and maximal infectivity of that host. Suppose females begin breeding at age and stop breeding (or die) at age, then the average age of first reproduction of a cohort of females is


T = \frac{\sum_{x=\alpha}^{\omega} x l(x) m(x) }{\sum_{x=\alpha}^{\omega} l(x) m(x) }

where is the hazard function and is the fecundity of females aged .

When the population is in stable age distribution, we can express the generation time as the average age of mothers of zero-year-olds:


T = \sum_{x=\alpha}^{\omega} x e^{-rx} l(x) m(x)

where is the Malthusian parameter of the population.

Famous quotes containing the words generation and/or time:

    They shall beget and rear children, handing on the torch of life from one generation to another.
    Plato (c. 427–347 B.C.)

    last time I saw you was the hospital
    pale skull protruding under ashen skin
    blue veined unconscious girl
    in an oxygen tent
    the war in Spain has ended long ago
    Aunt Rose
    Allen Ginsberg (b. 1926)