A statistically significant coefficient of the selection term indicates sample selection bias.
where ϵ ^ 2 ij are generalized residuals from the multilevel prenatal care model, and P ^ - 1 is the selection term.
We estimate this model by Ordinary Least Squares, obtain the predicted probabilities, P ^, construct the selection term, P ^ - 1, and include this selection term as an additional regressor in our model of primary interest [30].
c The Olsen approach involves estimation of a linear probability model of the selection equation, obtaining the probability of selection into the sample P ^, construction of the selection term P ^ - 1, and inclusion of this selection term as an additional regressor in the infant health equation [30].
where Z is an indicator of the adequacy of prenatal care use, Y is a vector of controls, ε ^ 2 are generalized residuals from the prenatal care model, P ^ - 1 is the selection term, and ε1 is a stochastic error term.
Here we focus on the recursion for the trait variance, (10) Δ m 2 = N − 1 N w 2 m 2 2 − 1 N m 2 + N − 1 N μ σ 2, which indicates that the one-generational change in the trait variance is equal to the sum of three terms: the natural selection term, the genetic drift term, and the mutation term.
Also, the denominator in the first (selection) term is the harmonic mean of w ¯, (H(w ¯ )), whereas all subsequent terms involve dividing by powers of the expected value of w ¯, (w ¯ ^ ).
The consensus sequence from that selection (termed FOB, which stands for folding optimized protein from Family B) differs from protein DX at 17 out of 80 positions.
