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 |