maxTestIU_func {EquiTrends} | R Documentation |
This is a supporting function of the maxEquivTest
function. It calculates the placebo coefficients and the absolute value of the placebo coefficients. It then calculates the critical value and p-values if an equivalence threshold is supplied for the test, according to Dette & Schumann (2024). If no equivalence threshold is supplied, it calculates the minimum equivalence threshold for which the null of non-negligible pre-trend differences can be rejected.
maxTestIU_func(
data,
equiv_threshold,
vcov,
cluster,
alpha,
n,
no_periods,
base_period,
is_panel_balanced
)
data |
The data.frame object containing the data for the test. Should be of the form what is returned by the EquiTrends_dataconstr function. |
equiv_threshold |
The equivalence threshold for the test. If NULL, the minimum equivalence threshold for which the null hypothesis of non-negligible can be rejected is calculated. |
vcov |
The variance-covariance matrix estimator. See maxEquivTest for more information. |
cluster |
The cluster variable for the cluster-robust variance-covariance matrix estimator. See maxEquivTest for more information. |
alpha |
The significance level for the test. |
n |
The number of cross-sectional individuals in the data. |
no_periods |
The number of periods in the data. |
base_period |
The base period for the test. Must be one of the unique periods in the data. |
is_panel_balanced |
A logical value indicating whether the panel data is balanced. |
An object of class "maxEquivTestIU" containing:
placebo_coefficients |
A numeric vector of the estimated placebo coefficients, |
abs_placebo_coefficients |
a numeric vector with the absolute values of estimated placebo coefficients, |
placebo_coefficient_se |
a numeric vector with the standard errors of the placebo coefficients, |
significance_level |
the chosen significance level of the test, |
num_individuals |
the number of cross-sectional individuals (n), |
num_periods |
the number of periods (T), |
num_observations |
the total number of observations (N), |
base_period |
the base period in the data, |
placebo_names |
the names corresponding to the placebo coefficients, |
equiv_threshold_specified |
a logical value indicating whether an equivalence threshold was specified. |
is_panel_balanced |
a logical value indicating whether the panel data is balanced. |
Additionally, if !(is.null(equiv_threshold))
IU_critical_values
: a numeric vector with the individual critical values for each of the placebo coefficients,
reject_null_hypothesis
: a logical value indicating whether the null hypothesis of negligible pre-trend differences can be rejected at the specified significance level alpha
,
equiv_threshold
: the equivalence threshold employed,
if is.null(equiv_threshold)
minimum_equiv_thresholds
: a numeric vector including for each placebo coefficient the minimum equivalence threshold for which the null hypothesis of negligible pre-trend differences can be rejected for the corresponding placebo coefficient individually,
minimum_equiv_threshold
: a numeric scalar minimum equivalence threshold for which the null hypothesis of negligible pre-trend differences can be rejected for all placebo coefficients individually.
Dette, H., & Schumann, M. (2024). "Testing for Equivalence of Pre-Trends in Difference-in-Differences Estimation." Journal of Business & Economic Statistics, 1–13. DOI: doi:10.1080/07350015.2024.2308121