Estimator

Formula

Comment

Non parametric (NP) Regression

T ^ N P = i s y i + j r h ^ ( x j )

Nonparametric (NPT) regression, twiced

T ^ N P T = i s y i h ^ ( x i ) π i + j U h ^ ( x j )

π i = Inclusion probabilities

Multiplicative (MBC) Bias Corrected

T ^ M B C = i s y i h ^ ( x i ) π i + j U h ^ ( x j )

π i = Inclusion probabilities