Shift treatment by a fixed amount

Description

Creates a modified treatment policy (MTP) that adds a fixed delta to each individual’s observed treatment value. Useful for continuous treatments where a population-level shift is the relevant intervention (e.g., "reduce exposure by 10 units").

Usage

shift(delta)

Arguments

delta Numeric. The amount to add to the observed treatment.

Value

A causatr_intervention object.

References

Diaz I, Williams N, Hoffman KL, Schenck EJ (2023). Non-parametric causal effects based on longitudinal modified treatment policies. Journal of the American Statistical Association 118:846-857.

See Also

static(), scale_by(), threshold(), dynamic(), ipsi()

Examples

library("causatr")

fit <- causat(nhefs, outcome = "wt82_71", treatment = "smokeintensity",
              confounders = ~ sex + age + wt71)
contrast(fit, interventions = list(
  reduce10 = shift(-10),
  observed = shift(0)
))