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Plot one or more event-study tibbles on a single panel

Source: R/nabs_event_plot.R
nabs_event_plot.Rd

Overlays event-study estimates from any combination of supported estimators on a single ggplot2 panel. Two visual encodings are available via `style`:

Usage

nabs_event_plot(
  ...,
  style = c("prepost_color", "method_shape"),
  connect = FALSE,
  connect_linewidth = 0.4,
  reference = NULL,
  reference_color = "grey20",
  palette = "default",
  shapes = NULL,
  xlim = NULL,
  ylim = NULL,
  dodge = 0.5,
  point_size = 2.5,
  errorbar_width = 0.1,
  x_break_by = 2,
  show_pre_post_legend = TRUE,
  xlab = "Relative time to treatment change",
  ylab = "Estimated effect",
  base_size = 11
)

Arguments

...

One or more `nabs_event_study_tbl` objects. Bare arguments and a single list are both accepted.

style

Visual encoding. One of `"prepost_color"` (default; color differs by pre/post) or `"method_shape"` (color and marker shape both encode the method, shared across pre/post).

connect

Logical. If `TRUE`, point estimates within each series are joined by a thin line. Default `FALSE`. The line is split at the treatment boundary so pre- and post-treatment segments are not joined across the discontinuity.

connect_linewidth

Width of the connecting line when `connect = TRUE`. Default `0.4`.

reference

Optional `nabs_event_study_tbl` to draw as a neutral-color reference layer (typically a naive TWFE estimate). Drawn under the main series.

reference_color

Color for the reference series. Default `"grey20"`.

palette

Either `"default"` (the package's built-in palette, patterned after the DCDH/PanelMatch/IFE conventions in the codebase this package was extracted from), `"colorblind"` (Okabe-Ito), or a named character vector of colors. For `style = "prepost_color"` the names are keyed by `"<method>_<window>"`, e.g. `c("DCDH_pre" = "#DE2D26", "DCDH_post" = "#3182BD", ...)`. For `style = "method_shape"` the names are keyed by `"<method>"`, e.g. `c("DCDH" = "#DE2D26", ...)`.

shapes

Optional named integer vector of plotting symbols keyed by `"<method>"`, used only when `style = "method_shape"`. Defaults to the package's built-in shape set.

xlim, ylim

Numeric length-2 vectors for axis limits. `NULL` lets ggplot2 choose.

dodge

Width of the position-dodge applied to points, lines, and error bars. The `reference` series shares this dodge with the main series, so all series (including the naive TWFE reference) get their own evenly-spaced horizontal slot and their CIs do not overlap. Default `0.5`.

point_size, errorbar_width

Aesthetic controls for the geom layers.

x_break_by

Spacing between x-axis ticks (default 2, giving ... -4, -2, 0, 2, 4, 6 ...). Event-study time is integer, so this avoids ggplot2's default half-integer breaks like 2.5.

show_pre_post_legend

Logical. Only relevant for `style = "prepost_color"`. If `TRUE`, the legend keys are labeled `"<method>; pre"` / `"<method>; post"`. If `FALSE`, only one key per method is shown. Default `TRUE`.

xlab, ylab

Axis labels.

base_size

Base font size passed to `theme_minimal()`.

Value

A `ggplot` object.

Details

* `"prepost_color"` (default) – each method gets its own color, with separate shades for pre- and post-treatment periods, mirroring common conventions in DCDH-style plots. Points are drawn as circles throughout. * `"method_shape"` – each method gets a single color *and* a single marker shape. Pre and post periods share both the color and the shape; they are told apart only by their position relative to time 0. Because method is double-encoded (color + shape), this style stays legible in grayscale.

An optional `reference` series – typically a naive TWFE fit from [naive_twfe()] – is drawn in a neutral color (default black) so the reader can see what the heterogeneity-robust estimators are correcting against.

Set `connect = TRUE` to join each series' point estimates with a thin line, in addition to the points and error bars.

Examples

dcdh_tidy <- as_nabs_event_study(
  data.frame(
    time = -2:3,
    estimate = c(-0.06, -0.02, 0.10, 0.22, 0.28, 0.31),
    std.error = 0.08
  ),
  method = "DCDH",
  outcome = "y"
)

ife_tidy <- as_nabs_event_study(
  data.frame(
    time = -2:3,
    estimate = c(-0.04, 0.00, 0.08, 0.18, 0.25, 0.27),
    std.error = 0.10
  ),
  method = "IFE",
  outcome = "y"
)

nabs_event_plot(dcdh_tidy, ife_tidy, xlim = c(-2, 3))

nabs_event_plot(dcdh_tidy, ife_tidy, style = "method_shape", connect = TRUE)