plot: Plot Cutoff Changes for rdlearn Objects

In rdlearn: Safe Policy Learning under Regression Discontinuity Design with Multiple Cutoffs

Plot Cutoff Changes for rdlearn Objects

Description

This function plots the changes in cutoff values relative to the baseline cutoffs for each group, under different combinations of the smoothness multiplier (M) and the cost of treatment (C).

Usage

plot(x, opt, ...)

Arguments

x	An object of class rdlearn returned by the rdlearn function.
opt	When set to "safe", it displays the derived safe cutoffs and the original cutoffs. When set to "dif", it displays the change in cutoffs.
...	additional arguments.

Value

A ggplot2 plot which also contains the distance measure between original cutoffs and safe cutoffs.

Examples

# Simulation Data B from Appendix D of Zhang et al. (2022)
set.seed(1)
n <- 300
X <- runif(n, -1000, -1)
G <- 2 * as.numeric(
I(0.01 * X + 5 + rnorm(n, sd = 10) > 0)
) +
as.numeric(
I(0.01 * X + 5 + rnorm(n, sd = 10) <= 0)
)
c1 <- -850
c0 <- -571
C <- ifelse(G == 1, c1, c0)
D <- as.numeric(X >= C)
coef0 <- c(-1.992230e+00, -1.004582e-02, -1.203897e-05, -4.587072e-09)
coef1 <- c(9.584361e-01, 5.308251e-04, 1.103375e-06, 1.146033e-09)
Px <- poly(X, degree = 3, raw = TRUE)
# Px = poly(X-735.4334-c1,degree=3,raw=TRUE) for Simulation A
Px <- cbind(rep(1, nrow(Px)), Px)
EY0 <- Px %*% coef0
EY1 <- Px %*% coef1
d <- 0.2 + exp(0.01 * X) * (1 - G) + 0.3 * (1 - D)
Y <- EY0 * (1 - D) + EY1 * D - d * as.numeric(I(G == 1)) + rnorm(n, sd = 0.3)

simdata_B_demo <- data.frame(Y,X,C)

# Learn new treatment assignment cutoffs
rdlearn_result <- rdlearn(
  y = "Y", x = "X", c = "C", data = simdata_B_demo,
  fold = 2, M = 0, cost = 0
)

# Summarise the learned policies
summary(rdlearn_result)

# Visualize the learned policies
plot(rdlearn_result, opt = "dif")
# The learned cutoff for Group 1 is the same as the baseline cutoff, because
# the baseline cutoff is set to equal to oracle cutoff in this simulation.

# Implement sensitivity analysis
sens_result <- sens(rdlearn_result, M = 1, cost = 0)
plot(sens_result, opt = "dif")

rdlearn documentation built on April 4, 2025, 5:17 a.m.