Nurgaliev's law

In population dynamics, Nurgaliev's equation says

$${dn \over dt} = an^2 - bn,$$

where n is the size of a population, a is a half of the average probability of a birth of a male (the same for females) of a potential arbitrary parents pair within a year, b is an average probability of a death of a person within a year.

The first term is twice proportional to the half of population (number of males and number of females). The second term is responsible for death rate and has clear and precise sense—in-average-constant distribution of death rate on age scale (babies risk at a birth, middle age risk to get traumatized, old men become ill). It is known to demographers, for example, that the probability of death within the first year of a life is precisely equal to similar probability for the 55th year of a life. Thus, in the given model the average person dies under the same law as an unstable atomic nucleus decay.

Sources

• "Law" of Two Hundred Billions" in Context of Civil Society ". In materials of Inter-regional scientific-practical conference "The Civil Society: Ideas, Reality, Prospects ", on April, 27th, 2006, Kazan-Zelenodolsk, p. 204-207. ISBN 5-8399-0153-9.