Increasing men's wages increases their fertility. Increasing women's wages decreases their fertility.

"We use longitudinal register data on Danish couples and labor income tax reforms, especially in 2009/2010, to pin down how fertility decisions are affected by changes in the marginal net wage rates of men and women, analogous to the elasticity of taxable income literature... We find strong asymmetric effects: Increased marginal net wages of women reduce fertility of couples, while increased marginal net wages of men increase fertility. Our results imply that the substitution effect between children and labor supply is dominating for women while the income effect is dominating for men."

Source: Fertility and Family Labor Supply (2022) https://dx.doi.org/10.2139/ssrn.4118084