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Plot the ATT(g,t) matrix from a Callaway-Sant'Anna event study

Source: R/plot_att_gt.R
plot_att_gt.Rd

Visualises the full cohort-by-period ATT(g,t) matrix stored in the att_gt attribute of an es_result object produced by run_es(estimator = "cs"). Two display styles are available:

  • "heatmap": a tile plot with calendar time \(t\) on the x-axis and cohort \(g\) on the y-axis, colour-filled by the point estimate. Cells whose pointwise confidence interval excludes zero are marked with a filled dot; cells that are simultaneously significant (when bootstrap data are available) are additionally marked with an open diamond.

  • "facet": one panel per cohort showing ATT(g,t) over calendar time \(t\) with a pointwise confidence ribbon, mirroring the style of plot_es(). A lighter simultaneous CI ribbon is overlaid when bootstrap data are available.

Both types draw a vertical dashed line at \(t = g\) (treatment onset) for each cohort.

Usage

plot_att_gt(
  x,
  type = c("heatmap", "facet"),
  ci_level = 0.95,
  zero_line = TRUE,
  theme = c("bw", "minimal", "classic"),
  color = "#B25D91FF",
  fill = "#B25D91FF",
  alpha = 0.2
)

# S3 method for class 'att_gt_result'
autoplot(object, ...)

Arguments

x

An es_result object returned by run_es(estimator = "cs"), or an att_gt_result data frame produced by extracting attr(x, "att_gt") and giving it class "att_gt_result".

type

"heatmap" (default) or "facet".

ci_level

Confidence level for pointwise intervals (default 0.95).

zero_line

Logical; draw a horizontal reference line at zero in the "facet" display (default TRUE).

theme

One of "bw" (default), "minimal", or "classic".

color

Line and point colour used in the "facet" display (default "#B25D91FF", matching plot_es()).

fill

Ribbon fill colour in the "facet" display (default "#B25D91FF").

alpha

Ribbon transparency in the "facet" display (default 0.2).

object

An att_gt_result object (extracted from an es_result via attr(result, "att_gt")).

...

Passed to plot_att_gt.

Value

A ggplot2::ggplot() object.

Bootstrap annotation

When attr(x, "bootstrap") is present (i.e., run_es() was called with bootstrap = TRUE), both plot types add simultaneous inference overlays sourced from the (g,t)-level bootstrap object.

See also

plot_es(), run_es()

Examples

if (FALSE) { # \dontrun{
cs_result <- run_es(data = mydata, outcome = y, time = year,
                    timing = g, unit = id, fe = ~id + year,
                    staggered = TRUE, estimator = "cs")
plot_att_gt(cs_result)
plot_att_gt(cs_result, type = "facet")
} # }