Package {spliv}

Type: Package
Title: Patterned Sensitivity Analysis for IV with Fixed Effects
Version: 0.2.1
Description: Patterned sensitivity analysis for instrumental-variables designs with fixed effects or other residualization steps. The package provides uniform Conley-style sensitivity as a baseline, researcher-specified direct-effect patterns, sensitivity paths and tipping points, and optional confirmatory Beyond Plausibly Exogenous diagnostics.
License: GPL-3
Encoding: UTF-8
Depends: R (≥ 4.1)
Imports: stats, graphics, fixest
Suggests: lfe, testthat (≥ 3.0.0), ggplot2, knitr, rmarkdown
Config/testthat/edition: 3
VignetteBuilder: knitr
URL: https://koren6684.github.io/spliv/, https://github.com/koren6684/spliv
BugReports: https://github.com/koren6684/spliv/issues
RoxygenNote: 7.3.3
NeedsCompilation: no
Packaged: 2026-08-03 13:42:02 UTC; orekoren
Author: Ore Koren [aut, cre]
Maintainer: Ore Koren <okoren@iu.edu>
Repository: CRAN
Date/Publication: 2026-08-03 17:20:02 UTC

spliv: Patterned Sensitivity Analysis for IV

Description

Matrix-based patterned sensitivity analysis for plausibly exogenous IV inference with fixed-effect residualization, researcher-specified direct-effect patterns, sensitivity paths over delta, and optional confirmatory BPE diagnostics.

Author(s)

Maintainer: Ore Koren okoren@iu.edu

See Also

Useful links:

Create a Confirmatory BPE Design Object

Description

Creates a researcher-specified design object for confirmatory BPE. The subset must be justified outside the outcome analysis and should represent a theoretically motivated instrument-inactive subset.

Usage

bpe_design(
  name,
  subset,
  rationale,
  variables_used = NULL,
  subset_type = NULL,
  pre_specified = TRUE,
  transportability_rationale = NULL,
  notes = NULL
)

Arguments

name

Short design name.

subset

Subset specification. Accepts a one-sided formula, a ⁠function(data)⁠, a logical vector of length nrow(data), or a character string naming a logical column in data.

rationale

Non-empty substantive justification for the subset.

variables_used

Optional character vector describing the design variables used to define the subset. This is required for function-based subsets unless the package can safely infer the variables.

subset_type

Optional short label such as "theory_defined" or "design_based".

pre_specified

Logical indicator for confirmatory use. Confirmatory BPE requires TRUE.

transportability_rationale

Optional at construction time. A non-empty description of why the direct effect learned in the subset may be informative for the target sample is required for confirmatory validation and estimation.

notes

Optional free-form notes.

Value

An object of class "spliv_bpe_design".

Examples

design <- bpe_design(
  "Inactive subset", ~ inactive,
  rationale = "The treatment channel is absent in this subset.",
  variables_used = "inactive", pre_specified = TRUE,
  transportability_rationale = "The same direct-effect mechanism applies to the target sample."
)
bpe_eval_subset(design, data.frame(inactive = c(TRUE, FALSE)))

Evaluate a Confirmatory BPE Subset

Description

Evaluates a bpe_design() object on a data frame and returns the resulting logical indicator.

Usage

bpe_eval_subset(design, data, max_na_share = 0.05)

Arguments

design

A bpe_design() object.

data

Data frame used for evaluation.

max_na_share

Maximum allowable share of NA values in the subset indicator before evaluation fails. The default is 0.05.

Value

A logical vector of length nrow(data).

Examples

design <- bpe_design("Inactive", ~ inactive,
  rationale = "The treatment channel is absent.")
bpe_eval_subset(design, data.frame(inactive = c(TRUE, FALSE)))

Explore Candidate BPE Subsets

Description

Explores user-supplied candidate subset definitions and reports diagnostics for transparent exploratory work. This function is not valid confirmatory BPE by itself. Confirmatory BPE requires a pre-specified bpe_design() object supplied to spliv() or bpe_validate_design().

Usage

bpe_explore_subsets(
  data,
  spec,
  rules = NULL,
  seed = 1,
  min_n_S = NULL,
  min_varZ_S = NULL,
  return_all = TRUE
)

Arguments

data

Data frame used for estimation.

spec

Either an IV formula (y ~ X | Z) or a list with at least formula, and optional fe, fe_engine, and z_names.

rules

Candidate subset definitions. Each candidate may be a one-sided formula evaluated in data, a ⁠function(data)⁠ returning a logical vector, a character string naming a logical column in data, a logical vector of length nrow(data), or a named list with components name and subset.

seed

Integer seed for deterministic rule evaluation.

min_n_S

Optional exploratory screen for subset size.

min_varZ_S

Optional exploratory screen for within-subset residualized instrument variance.

return_all

If TRUE (default), returns all candidates and diagnostics. If FALSE, returns the first candidate in the user-supplied order. No automatic subset search or confirmatory selection is performed.

Details

Warning: this function is exploratory. It should not be used for confirmatory BPE inference. Confirmatory BPE requires a pre-specified bpe_design() object with a substantive rationale.

Value

If return_all = TRUE, a data frame with one row per rule and a list column subset. If return_all = FALSE, a list with the first supplied subset, rule, and diagnostics.

Examples

d <- data.frame(y = rnorm(40), x = rnorm(40), z = rnorm(40),
  inactive = rep(c(TRUE, FALSE), each = 20))
suppressWarnings(bpe_explore_subsets(
  d, y ~ x | z, rules = list(inactive = ~ inactive)))

Validate a Confirmatory BPE Design

Description

Runs the confirmatory BPE eligibility diagnostics for a pre-specified design without fitting the final SPLIV model.

Usage

bpe_validate_design(
  formula,
  data,
  design,
  fe = NULL,
  fe_engine = c("fixest", "lfe"),
  vcov = c("iid", "hc1", "cluster"),
  cluster = NULL,
  z_names = NULL,
  bpe_min_n_S = 2000,
  bpe_min_clusters_S = 30,
  bpe_min_varZ_S = 1e-06,
  bpe_equiv_margin,
  bpe_equiv_level = 0.95,
  bpe_transport = c("sampling", "conservative"),
  bpe_transport_kappa = 0,
  bpe_kappa = 1,
  scale_instrument = c("residual_sd", "none")
)

Arguments

formula

IV formula y ~ X | Z.

data

Data frame.

design

A bpe_design() object.

fe

Optional one-sided formula of fixed effects.

fe_engine

FE demeaning engine, one of "fixest" or "lfe".

vcov

One of "iid", "hc1", or "cluster".

cluster

Cluster ids or one-sided formula when vcov = "cluster".

z_names

Optional instrument name for BPE. Confirmatory BPE currently supports exactly one instrument.

bpe_min_n_S

Minimum subset size threshold.

bpe_min_clusters_S

Minimum number of clusters required in the subset when clustered covariance is used.

bpe_min_varZ_S

Minimum residualized instrument variance required in the subset.

bpe_equiv_margin

Researcher-specified equivalence margin. With scale_instrument = "residual_sd", this bounds the first-stage effect in residual treatment standard deviations associated with a one-residual-SD instrument shift. With scale_instrument = "none", it bounds the raw first-stage coefficient. Eligibility uses the corresponding confidence interval, not the first-stage F-statistic.

bpe_equiv_level

Confidence level used for the first-stage equivalence interval.

bpe_transport

One of "sampling" or "conservative". Sampling uses the estimated reduced-form sampling covariance. Conservative adds the documented inflation controlled by bpe_transport_kappa.

bpe_transport_kappa

Non-negative scalar controlling the conservative transport covariance inflation.

bpe_kappa

Positive scalar multiplier applied to the transported BPE covariance before it is embedded into the LTZ prior.

scale_instrument

One of "residual_sd" or "none".

Value

An object of class "spliv_bpe_validation" containing design metadata, subset diagnostics, first-stage equivalence diagnostics, reduced- form direct-effect estimates, and covariance components for confirmatory BPE.

Examples

set.seed(2)
d <- data.frame(
  y = rnorm(80), x = rnorm(80), z = rnorm(80),
  inactive = rep(c(TRUE, FALSE), each = 40)
)
design <- bpe_design("Inactive", ~ inactive,
  rationale = "The treatment channel is absent.",
  transportability_rationale = "The direct-effect mechanism applies to the target sample.")
bpe_validate_design(y ~ x | z, d, design,
  bpe_min_n_S = 20, bpe_equiv_margin = 1)

Plot Patterned Sensitivity Output or a Fitted Object

Description

Plot Patterned Sensitivity Output or a Fitted Object

Usage

plot_sp_sensitivity(
  df_plot,
  term = NULL,
  ylab = "Effect (beta)",
  main = "Plausibly Exogenous IV Sensitivity",
  ...
)

Arguments

df_plot

Data frame returned by a sensitivity helper or a spliv_fit object.

term

Optional term to plot when df_plot is a sensitivity-path object. If omitted, the first term is plotted (with a warning for multiple terms).

ylab

Y-axis label.

main

Plot title.

...

Additional graphics arguments forwarded to the sensitivity-path plotting method; ignored for fitted objects and ordinary data frames.

Value

Invisibly returns the plotted input.

Examples

set.seed(7)
d <- data.frame(y = rnorm(80), x = rnorm(80), z = rnorm(80))
p <- spliv_sensitivity_path(y ~ x | z, d, method = "uci", delta_grid = c(0, 0.1))
plot_sp_sensitivity(p, term = "x")

Local-to-Zero Inference for Plausibly Exogenous IV

Description

Formula-level wrapper over the matrix core LTZ implementation.

Usage

sp_ltz(
  formula,
  data,
  omega,
  mu,
  level = 0.95,
  vcov = c("hc1", "hc0", "iid", "cluster"),
  cluster = NULL
)

Arguments

formula

IV formula y ~ X | Z.

data

Data frame.

omega

Prior covariance matrix over instrument direct effects.

mu

Prior mean vector over instrument direct effects.

level

Confidence level.

vcov

One of "iid", "hc0", "hc1", "cluster".

cluster

Cluster ids when vcov = "cluster".

Value

Data frame with adjusted estimates and confidence intervals.

Examples

set.seed(3)
d <- data.frame(y = rnorm(80), x = rnorm(80), z = rnorm(80))
prior <- sp_prior_ltz(y ~ x | z, d, inst_vary = "z", sd = 0.1)
sp_ltz(y ~ x | z, d, prior$omega, prior$mu)

Build LTZ Prior Matrices for Chosen Instruments

Description

Build LTZ Prior Matrices for Chosen Instruments

Usage

sp_prior_ltz(
  formula,
  data = NULL,
  inst_vary,
  mean = 0,
  sd = 1,
  vcov = c("hc1", "hc0", "iid", "cluster"),
  cluster = NULL
)

Arguments

formula

Formula or spliv_fit.

data

Data frame when formula is a formula.

inst_vary

Instrument(s) with non-degenerate prior.

mean

Prior mean(s).

sd

Prior sd(s).

vcov

Vcov type.

cluster

Optional cluster ids.

Value

List with mu, omega, and instrument names.

Examples

set.seed(9)
d <- data.frame(y = rnorm(60), x = rnorm(60), z = rnorm(60))
sp_prior_ltz(y ~ x | z, d, inst_vary = "z", sd = 0.1)

LTZ Sensitivity over Delta Grid

Description

LTZ Sensitivity over Delta Grid

Usage

sp_sensitivity_ltz_normal(
  formula,
  data = NULL,
  term,
  inst_vary,
  delta_grid,
  mean_fun = function(delta) 0,
  sd_fun = function(delta) delta,
  level = 0.95,
  vcov = c("hc1", "hc0", "iid", "cluster"),
  cluster = NULL,
  scale_instrument = c("residual_sd", "none")
)

Arguments

formula

Formula or spliv_fit.

data

Data frame when formula is a formula.

term

Coefficient name to track.

inst_vary

Instrument(s) with plausible violation.

delta_grid

Delta grid.

mean_fun

Function mapping delta to prior mean.

sd_fun

Function mapping delta to prior sd.

level

Confidence level.

vcov

Vcov type.

cluster

Optional cluster ids.

scale_instrument

One of "residual_sd" (default) or "none".

Value

Data frame with sensitivity path.

Examples

set.seed(10)
d <- data.frame(y = rnorm(60), x = rnorm(60), z = rnorm(60))
sp_sensitivity_ltz_normal(y ~ x | z, d, term = "x", inst_vary = "z",
  delta_grid = c(0, 0.1), scale_instrument = "none")

LTZ Sensitivity with Normal Approximation to U(0, delta)

Description

LTZ Sensitivity with Normal Approximation to U(0, delta)

Usage

sp_sensitivity_ltz_uniform01_as_normal(
  formula,
  data = NULL,
  term,
  inst_vary,
  delta_grid,
  level = 0.95,
  vcov = c("hc1", "hc0", "iid", "cluster"),
  cluster = NULL,
  scale_instrument = c("residual_sd", "none")
)

Arguments

formula

Formula or spliv_fit.

data

Data frame when formula is a formula.

term

Coefficient name to track.

inst_vary

Instrument(s) with plausible violation.

delta_grid

Delta grid.

level

Confidence level.

vcov

Vcov type.

cluster

Optional cluster ids.

scale_instrument

One of "residual_sd" (default) or "none".

Value

Data frame with sensitivity path.

Examples

set.seed(12)
d <- data.frame(y = rnorm(60), x = rnorm(60), z = rnorm(60))
sp_sensitivity_ltz_uniform01_as_normal(y ~ x | z, d, term = "x",
  inst_vary = "z", delta_grid = c(0, 0.1), scale_instrument = "none")

UCI Sensitivity over Delta Grid

Description

UCI Sensitivity over Delta Grid

Usage

sp_sensitivity_uci_support(
  formula,
  data = NULL,
  term,
  inst_vary,
  delta_grid,
  gmin_fun = function(delta) -delta,
  gmax_fun = function(delta) delta,
  grid = 41,
  level = 0.95,
  vcov = c("hc1", "hc0", "iid", "cluster"),
  cluster = NULL,
  scale_instrument = c("residual_sd", "none")
)

Arguments

formula

Formula or spliv_fit.

data

Data frame when formula is a formula.

term

Coefficient name to track.

inst_vary

Instrument(s) whose gamma bounds vary.

delta_grid

Delta grid.

gmin_fun

Function mapping delta to lower bound.

gmax_fun

Function mapping delta to upper bound.

grid

Points per instrument bound.

level

Confidence level.

vcov

Vcov type.

cluster

Optional cluster ids.

scale_instrument

One of "residual_sd" (default) or "none".

Value

Data frame with sensitivity path.

Examples

set.seed(11)
d <- data.frame(y = rnorm(60), x = rnorm(60), z = rnorm(60))
sp_sensitivity_uci_support(y ~ x | z, d, term = "x", inst_vary = "z",
  delta_grid = c(0, 0.1), grid = 5, scale_instrument = "none")

Union of Confidence Intervals for Plausibly Exogenous IV

Description

Formula-level wrapper over the matrix core UCI implementation.

Usage

sp_uci(
  formula,
  data,
  inst,
  gmin,
  gmax,
  grid = 21,
  level = 0.95,
  vcov = c("hc1", "hc0", "iid", "cluster"),
  cluster = NULL
)

Arguments

formula

IV formula y ~ X | Z.

data

Data frame.

inst

Instrument names to vary.

gmin

Lower bound(s) on gamma.

gmax

Upper bound(s) on gamma.

grid

Grid size per varied instrument.

level

Confidence level.

vcov

One of "iid", "hc0", "hc1", "cluster".

cluster

Cluster ids when vcov = "cluster".

Value

Data frame with union confidence intervals.

Examples

set.seed(4)
d <- data.frame(y = rnorm(80), x = rnorm(80), z = rnorm(80))
sp_uci(y ~ x | z, d, inst = "z", gmin = -0.1, gmax = 0.1, grid = 5)

Patterned Sensitivity Analysis for Plausibly Exogenous IV

Description

Main estimator for patterned sensitivity analysis of exclusion violations in fixed-effect or residualized IV designs.

Usage

spliv(
  formula,
  data,
  fe = NULL,
  fe_engine = c("fixest", "lfe"),
  vcov = c("iid", "hc1", "cluster"),
  cluster = NULL,
  method = c("uci", "ltz", "bpe"),
  prior = NULL,
  delta = NULL,
  violation_pattern = NULL,
  bpe_design = NULL,
  bpe_kappa = 1,
  bpe_min_n_S = 2000,
  bpe_min_clusters_S = 30,
  bpe_min_varZ_S = 1e-06,
  bpe_equiv_margin = NULL,
  bpe_equiv_level = 0.95,
  bpe_transport = c("sampling", "conservative"),
  bpe_transport_kappa = 0,
  bpe_not_applicable = c("na", "error"),
  scale_instrument = c("residual_sd", "none"),
  grid = list()
)

Arguments

formula

IV formula y ~ X | Z. Ordinary exogenous controls must appear on both sides, for example y ~ x + w | z + w.

data

Data frame.

fe

Optional one-sided formula of fixed effects.

fe_engine

FE demeaning engine, one of "fixest" or "lfe".

vcov

One of "iid", "hc1", or "cluster".

cluster

Cluster ids or one-sided formula, required when vcov = "cluster".

method

One of "uci", "ltz", or "bpe". The default is the conventional UCI analysis.

prior

Optional prior list with mu and Omega (or omega) for LTZ. When violation_pattern is supplied, patterned LTZ currently requires a scalar prior over the pattern coefficient.

delta

Optional non-negative scalar sensitivity magnitude. With scale_instrument = "residual_sd", delta is the direct outcome effect of a one-residual-SD instrument shift. With scale_instrument = "none", it is the raw direct-effect coefficient. For UCI, delta supplies symmetric bounds ⁠[-delta, +delta]⁠; for LTZ without an explicit prior, it is the standard deviation of a zero-mean normal direct-effect prior.

violation_pattern

Optional spliv_pattern() object describing how the direct effect of the instrument may vary across observations. If omitted, LTZ/UCI use the uniform direct-effect behavior. This argument is currently supported for LTZ and UCI, but not for confirmatory BPE.

bpe_design

A pre-specified bpe_design() object for confirmatory BPE. A non-empty subset rationale and transportability rationale are required when method = "bpe".

bpe_kappa

Positive scalar multiplier applied to the confirmatory BPE covariance after transport adjustment.

bpe_min_n_S

Minimum subset size required for BPE eligibility. Default 2000.

bpe_min_clusters_S

Minimum number of clusters required in subset S when vcov = "cluster". Default 30.

bpe_min_varZ_S

Minimum residualized instrument variance required in subset S. Default 1e-6.

bpe_equiv_margin

Researcher-specified first-stage equivalence margin. With scale_instrument = "residual_sd", the margin is measured in residual treatment standard deviations per one-residual-SD instrument shift. With scale_instrument = "none", it is on the raw first-stage coefficient scale. Confirmatory BPE currently supports one treatment and one instrument.

bpe_equiv_level

Confidence level for the first-stage equivalence check.

bpe_transport

One of "sampling" or "conservative". Sampling uses the estimated reduced-form sampling covariance; conservative adds the inflation controlled by bpe_transport_kappa.

bpe_transport_kappa

Non-negative scalar controlling the conservative transport covariance inflation.

bpe_not_applicable

Behavior when subset diagnostics fail. One of "na" (default) to return NA estimates, or "error" to stop.

scale_instrument

One of "residual_sd" (default) or "none".

grid

List controlling UCI bounds or other tuning parameters. For scalar UCI, if grid$delta is supplied and grid$gmin/grid$gmax are omitted, the package interprets delta as a direct-effect bound of ⁠[-delta, +delta]⁠ under the chosen scale_instrument. When violation_pattern is supplied, grid$delta instead refers to theta bounds over the pattern-scaled direct effect.

Details

UCI is the union of conventional IV confidence intervals over the specified direct-effect bounds. LTZ propagates a local-to-zero prior mean and covariance for the direct effect into the IV estimate and uncertainty.

spliv implements patterned sensitivity analysis for exclusion violations in IV designs with fixed effects or other residualization steps. Researchers can supply a theoretically motivated spliv_pattern() object to specify where direct effects of an instrument are expected to be larger or smaller, and the package then scales LTZ/UCI sensitivity along that pattern.

The package does not estimate an unrestricted direct-effect field. Instead, researchers supply a structured pattern and ask whether conclusions survive direct effects scaled along that pattern.

In applied work, users should usually vary delta over a range with spliv_sensitivity_path() rather than report one arbitrary sensitivity value.

Patterned sensitivity currently supports one endogenous treatment, one excluded instrument, and one researcher-specified pattern at a time.

Confirmatory BPE is not a subgroup-search procedure. The researcher must supply a pre-specified bpe_design() object, the package validates that subset, documents why its direct effect is transportable to the target sample, and BPE proceeds only if the confirmatory eligibility checks pass.

The first-stage F-statistic is still reported for diagnostics, but confirmatory BPE eligibility is determined by the pre-specification checks, subset size, cluster count, residualized instrument variation, and a first-stage equivalence interval.

BPE reduced-form covariance is propagated as a full covariance matrix and can optionally be inflated via bpe_transport.

Value

Object of class spliv_fit.

Examples

set.seed(1)
d <- data.frame(y = rnorm(60), x = rnorm(60), z = rnorm(60), w = rnorm(60))
fit <- spliv(y ~ x + w | z + w, d)
fit$estimates

Evaluate a Direct-Effect Pattern

Description

Evaluates a spliv_pattern() object on a data frame and returns a numeric vector after optional centering and normalization.

Usage

spliv_eval_pattern(pattern, data)

Arguments

pattern

A spliv_pattern() object.

data

Data frame used for evaluation.

Value

Numeric vector of length nrow(data).

Examples

d <- data.frame(exposure = seq(-1, 1, length.out = 5))
p <- spliv_pattern("Exposure", ~ exposure,
  rationale = "Illustration of a monotone exposure pattern.")
spliv_eval_pattern(p, d)

Create a Patterned Exclusion-Violation Object

Description

Creates a researcher-specified direct-effect pattern for patterned sensitivity analysis. The pattern determines where direct effects of the instrument are expected to be larger or smaller in the estimation sample.

Usage

spliv_pattern(
  name,
  pattern,
  rationale,
  variables_used = NULL,
  pattern_type = NULL,
  normalize = c("max_abs", "sd", "none"),
  center = FALSE,
  pre_specified = TRUE,
  notes = NULL
)

Arguments

name

Short pattern name.

pattern

Pattern specification. Accepts a one-sided formula, a ⁠function(data)⁠, a numeric vector of length nrow(data), a logical vector of length nrow(data), or a character string naming a numeric or logical column in data.

rationale

Substantive justification for the proposed pattern.

variables_used

Optional character vector describing the variables used to define the pattern.

pattern_type

Optional short label such as "theory_defined" or "design_based".

normalize

One of "max_abs" (default), "sd", or "none".

center

Logical; if TRUE, subtracts the estimation-sample mean before normalization.

pre_specified

Logical indicator for whether the pattern was chosen before examining outcome results.

notes

Optional free-form notes.

Value

An object of class "spliv_pattern".

Examples

p <- spliv_pattern(
  name = "Exposure", pattern = ~ exposure,
  rationale = "The alternative channel follows exposure.",
  variables_used = "exposure", pattern_type = "theory_defined"
)
p$name

Sensitivity Path over Delta Grid

Description

Runs spliv() repeatedly over a user-supplied delta_grid and returns a tidy sensitivity-path object. This is the recommended workflow for patterned or uniform sensitivity analysis: users should usually report how intervals change over a range of delta values rather than selecting one arbitrary sensitivity level.

Usage

spliv_sensitivity_path(
  formula,
  data,
  method = c("uci", "ltz"),
  delta_grid = seq(0, 0.2, by = 0.01),
  violation_pattern = NULL,
  stop_on_error = TRUE,
  ...
)

Arguments

formula

IV formula y ~ X | Z.

data

Data frame.

method

One of "uci" or "ltz". spliv_sensitivity_path() intentionally excludes confirmatory BPE.

delta_grid

Non-negative sensitivity grid. For UCI, each value d implies theta bounds ⁠[-d, +d]⁠.

violation_pattern

Optional spliv_pattern() object. If omitted, the path uses a uniform direct-effect pattern.

stop_on_error

Logical; if TRUE (default), stop on the first failed fit. If FALSE, record NA rows and store the error message in the returned error column.

...

Additional named arguments passed through to spliv(), such as fe, vcov, cluster, scale_instrument, or grid = list(level = 0.95).

Value

A data frame with class c("spliv_sensitivity_path", "data.frame"). The returned object includes path columns such as delta, method, estimate, conf_low, conf_high, contains_zero, and pattern metadata, plus attributes containing the original call, the supplied grid, and a tipping-point summary.

Examples

set.seed(5)
d <- data.frame(y = rnorm(80), x = rnorm(80), z = rnorm(80))
p <- spliv_sensitivity_path(y ~ x | z, d, method = "uci",
  delta_grid = c(0, 0.1), vcov = "hc1")
head(p)

Extract Tipping-Point Delta from a Sensitivity Path

Description

Returns the tipping-point attribute stored on a spliv_sensitivity_path() object. For each term, the tipping point is the smallest delta on the supplied grid whose interval includes zero.

Usage

spliv_tipping_point(x)

Arguments

x

A spliv_sensitivity_path object.

Value

Named numeric vector of tipping-point values.

Examples

set.seed(6)
d <- data.frame(y = rnorm(80), x = rnorm(80), z = rnorm(80))
p <- spliv_sensitivity_path(y ~ x | z, d, method = "uci", delta_grid = c(0, 0.1))
spliv_tipping_point(p)