Discrete Euler-Lotka equation

For annual survival probabilities $1-{\mu }_i$, age-specific offspring numbers $b_a$, and a population multiplier $\gamma$, the discrete Euler-Lotka equation isIts value at $\gamma =1$ is the expected lifetime offspring count of a newborn under the fixed vital rates. A value above one implies a growing mode $\gamma >1$, while a value below one implies decline.