Notation

Symbols used throughout the package vignettes (see Leventer 2025, §2–3 for formal definitions):

Symbol	Definition
$G \in \{f,m\}$	Gender (female, male)
$D$	Age at first childbirth (treatment timing)
$Y_{i,a}(d)$	Potential earnings of individual $i$ at age $a$ if first birth occurs at age $d$
$Y_{i,a}(\infty)$	Potential earnings under never having a child
$\text{APO}(g,d,a) = \mathbb{E}[Y_a(\infty) \mid G=g, D=d]$	Average counterfactual earnings
$\text{ATE}(g,d,a) = \mathbb{E}[Y_a(d) - Y_a(\infty) \mid G=g, D=d]$	Average treatment effect of parenthood
$\theta(g,d,a) = \text{ATE}/\text{APO}$	Normalised effect (proportional earnings change)
$\rho(d,a) = \text{APO}(f,d,a) / \text{APO}(m,d,a)$	Gender earnings ratio (counterfactual)
$\Delta\rho(d,a)$	Effect of parenthood on the gender earnings ratio