Comparison of select marginal effects in linear versions of models 1, 2, and 3.

Source: Collaborative Perinatal Project (CPP). Notes: All three models specify linear relationships between the dependent and independent variables and are estimated by ordinary least squares. Robust standard errors are in parentheses, and asterisks denote statistical significance at the 1% (***), 5% (**), and 10% (*) level. Model 1 includes the following covariates: mother's age, father's age, child's age, getstation weeks, child's sex, mother's race/ethnicity. Model 2 includes those covariates plus mother's marital status, family's socioeconomic index, and mother's and father's past mental illness (indicator variables). Model 3 includes those covariates plus mother's and father's education, number of older siblings, number of younger siblings (at 7 years) and birth weight.