qte 2.0.0

This is a major update that extends all estimators to support staggered treatment adoption. The API has changed substantially — please read this section before upgrading.

New functions

unc_qte() — cross-sectional QTE and QTT under unconfoundedness. Supports IPW, outcome regression, and doubly robust (AIPW) estimation. Uses a yname/dname interface consistent with the did/ptetools convention. Replaces ci.qte() and ci.qtet(), which are retained as deprecated wrappers.
cic() / cic_gt() — Change in Changes estimator for staggered treatment adoption (Athey and Imbens 2006). Supports panel and repeated cross sections data, and returns either ATT (gt_type = "att") or a full QTT curve (gt_type = "qtt"). Replaces CiC(), which is retained as a deprecated wrapper.
qdid() / qdid_gt() — Quantile Difference in Differences estimator for staggered treatment adoption (Callaway, Li, and Oka 2018). Replaces QDiD(), which is retained as a deprecated wrapper.
mdid() / mdid_gt() — Mean Difference in Differences estimator for staggered treatment adoption (Callaway and Li 2019). Replaces MDiD(), which is retained as a deprecated wrapper.
ddid() / ddid_gt() — Distributional Difference in Differences estimator for staggered treatment adoption (Callaway and Li 2019). Replaces ddid2(), which is retained as a deprecated wrapper.
panel_qtt() / panel_qtt_gt() — Panel QTT estimator using copula transfer across pre-treatment periods (Callaway and Li 2019), with staggered treatment adoption support. The pre_copula argument controls whether a rolling ("long", default) or fixed ("short") base period is used to transfer the copula. Replaces panel.qtet(), which is retained as a deprecated wrapper.
lou_qtt() — Lagged-outcome unconfoundedness QTT estimator for staggered treatment adoption. Uses the lagged outcome as a control variable to identify the QTT. New; no prior equivalent in the package.

Deprecated functions

The following functions emit a runtime deprecation warning via .Deprecated() and will be removed in v2.1 (target: 2026-08). Each points to its modern replacement in the warning message.

Deprecated	Replacement
`ci.qte()`	`unc_qte(target = "qte")`
`ci.qtet()`	`unc_qte(target = "qtt")`
`CiC()`	`cic()`
`QDiD()`	`qdid()`
`MDiD()`	`mdid()`
`ddid2()`	`ddid()`
`panel.qtet()`	`panel_qtt()`

Removed functions

computeDiffSE() — was dead code; never called anywhere in the package. Design notes for a future QTT-vs-ATT test are in dev/NOTES.md.
DR(), spatt(), bounds() — removed in earlier 1.5.x development work.
qtes2mat(), diffQ() — formatting helpers tied to the legacy QTE class with no internal callers.

Infrastructure

Full testthat test suite added (83 fast tests; 10 slow bootstrap tests skipped by default, enabled via R_SLOW_TESTS=true). The package previously had no tests.
All new estimators are backed by ptetools::pte(). The attgt_fun hook pattern makes it straightforward to add new identification strategies without duplicating bootstrap or aggregation code.
Estimators now pass an explicit aggte_fun to ptetools::pte(), replacing the earlier implicit dispatch based on gt_type.
ptetools added to Imports (was missing from DESCRIPTION despite being used).
Hmisc and texreg removed from Imports (were unused after earlier cleanup).
License updated from GPL-2 to GPL-3.

qte 1.4.0

Added cic2() for Change in Changes with multiple periods and variation in treatment timing, using ptetools as a backend. This function was experimental; it has been superseded by cic() in v2.0.0.

qte 1.3.3

Bug fix: critical values for uniform confidence bands now correctly reflect the alp argument rather than being stuck at alp = 0.05.

qte 1.3.2

Significance level is now passed through in the results.
Added ability to change significance level in ggqte() for pointwise confidence intervals without re-estimating.

qte 1.3.1

Updated maintainer contact information.
Improvements and updates to vignettes.

qte 1.3.0

Added first-step quantile regression support for panel.qtet(), QDiD(), and CiC().
Added checks that input data is in the correct format, particularly for panel data.

qte 1.2.3

Now using empirical quantiles in the CiC method.
Added code for computing uniform confidence bands.
General improvements to the codebase, including combining shared code across methods.

qte 1.2.2

Bug fixes to the CiC method.

qte 1.2

Added ddid2() to compute quantile treatment effects under a Difference in Differences assumption following Callaway and Li (2016).
Covariates for all methods now specified using formulas (xformla argument) rather than passing variable names directly.
Improvements to bootstrapping standard errors.
Some extensions to computing the ATT via spatt().
Preliminary version of multi-period ATT moved to the did package.