diff_diff.changes_in_changes_results.ChangesInChangesResults

class diff_diff.changes_in_changes_results.ChangesInChangesResults

Bases: object

Results for ChangesInChanges and QDiD.

The headline att/se/t_stat/p_value/conf_int fields carry the mean effect; quantile_effects is a DataFrame with one row per requested quantile (columns quantile, qte, se, t_stat, p_value, conf_low, conf_high). All inference derives from the bootstrap (replicate-SD standard errors, symmetric normal-approximation intervals at level alpha); with n_bootstrap=0 every inference field is NaN.

q_lower/q_upper bound the point-identified interior quantile range for unconditional CiC fits (Athey-Imbens eq. 17; NaN for QDiD and for covariate fits, where the unconditional bounds are not the relevant objects). sup_t_crit is the qte package’s sup-t critical value for uniform bands - computed at a FIXED 95% level regardless of alpha (qte parity); see uniform_bands(). covariates records the covariate columns used by the conditional (quantile-regression) fit, or None for unconditional fits.

Methods

__init__(att, se, t_stat, p_value, conf_int, ...)
print_summary()	Print summary() to stdout.
summary()	Fixed-width text summary: headline ATT block plus the quantile-effects table.
to_dataframe([level])	Return the quantile-effects table or the one-row ATT summary.
to_dict()	Flat headline dictionary (ATT inference, ranges, sizes, bootstrap metadata).
uniform_bands()	Simultaneous (sup-t) confidence bands over the quantile grid.

Attributes

alpha
covariates
is_significant	Whether the headline ATT is significant at level alpha (False on NaN).
significance_stars	Significance stars for the headline ATT p-value ('' when NaN).
att
se
t_stat
p_value
conf_int
quantile_effects
q_lower
q_upper
sup_t_crit
n_obs
cell_sizes
n_bootstrap
n_bootstrap_valid
panel
estimator
quantiles

__init__(att, se, t_stat, p_value, conf_int, quantile_effects, q_lower, q_upper, sup_t_crit, n_obs, cell_sizes, n_bootstrap, n_bootstrap_valid, panel, estimator, quantiles, alpha=0.05, covariates=None)

Parameters:

• att (float)

• se (float)

• t_stat (float)

• p_value (float)

• conf_int (Tuple[float, float])

• quantile_effects (DataFrame)

• q_lower (float)

• q_upper (float)

• sup_t_crit (float)

• n_obs (int)

• cell_sizes (Dict[str, int])

• n_bootstrap (int)

• n_bootstrap_valid (int)

• panel (bool)

• estimator (str)

• quantiles (ndarray)

• alpha (float)

• covariates (List[str] | None)

Return type:

None

classmethod __new__(*args, **kwargs)