gen_a_start: gen_a_start

In OVtool: Omitted Variable Tool

Description

This function is a wrapper to ov_simgrid. It generates the a. a is used to control the strength of the relationshp between the unobserved counfounder, U, and the treatment indicator

Usage

gen_a_start(y, tx, residuals, es, rho, my_estimand)

Arguments

y	A vector that represents the outcome.
tx	A vector for the treatment indicator (must be 0s and 1s).
residuals	A vector of residuals from regressing Y on X and controlling for treatment.
es	An effect size value to simulate over.
rho	A rho (correlation) value to simulate over.
my_estimand	"ATE" or "ATT"

Value

gen_a_start returns a list containing the following components:

n1	scalar representing sample size of treatment group (treat == 1)
ve1	1 - b1^2 multiplied by the variance of Ystar1
b1	bounded parameter for treatment group (treat == 1) that it with b0 are selected to set the correlation of the omitted variable and the outcome equal to rho
es
pi	proportion of population that is in the treatment group (treat == 1)
n0	scalar represnting sample size of control group (treat == 0)
ve0	1 - b0^2 multiplied by the variance of Ystar0
b0	bounded parameter for control group (treat == 0) that it with b1 are selected to set the correlation of the omitted variable and the outcome equal to rho
n	scalar representing the total sample size
ind	vector of positions in data that represent treatment group (treat == 1)
Rstar_1	Residuals in treatment group
Rstar_0	Residuals in control group

Examples

data(sud)
sud = data.frame(sud)
sud$treat = ifelse(sud$treat == "A", 1, 0)
sud$wts = sample(seq(1, 10, by=.01), size=nrow(sud), replace = TRUE)
outcome_mod = outcome_model(data = sud,
                            weights = "wts",
                            treatment = "treat",
                            outcome = "eps7p_3",
                            model_covariates = c("sfs8p_0"),
                            estimand = "ATE")

start = gen_a_start(y=sud$eps7p_3, tx=sud$treat,
                    residuals=residuals(outcome_mod$mod_results),
                    es = .01,
                    rho = .01,
                    my_estimand = "ATE")

OVtool documentation built on Nov. 2, 2021, 9:07 a.m.