Bump version to 3.1.1

Jackknife variance estimation for SyntheticDiD and dCDH LinkedIn
carousel.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: igerber

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [3.1.1] - 2026-04-16
+
+### Added
+- **Jackknife variance estimation for SyntheticDiD** - `variance_method='jackknife'` implements the delete-one-unit jackknife from Arkhangelsky et al. (2021) Section 5. Supports both standard and survey-weighted jackknife with automatic `pweight` propagation. Validated against R `synthdid` package.
+- **LinkedIn carousel** for dCDH estimator announcement (`carousel/diff-diff-dcdh-carousel.pdf`)
+
 ## [3.1.0] - 2026-04-14
 
 ### Added
@@ -1289,6 +1295,7 @@ for the full feature history leading to this release.
 [2.1.2]: https://github.com/igerber/diff-diff/compare/v2.1.1...v2.1.2
 [2.1.1]: https://github.com/igerber/diff-diff/compare/v2.1.0...v2.1.1
 [2.1.0]: https://github.com/igerber/diff-diff/compare/v2.0.3...v2.1.0
+[3.1.1]: https://github.com/igerber/diff-diff/compare/v3.1.0...v3.1.1
 [3.1.0]: https://github.com/igerber/diff-diff/compare/v3.0.2...v3.1.0
 [3.0.2]: https://github.com/igerber/diff-diff/compare/v3.0.1...v3.0.2
 [2.0.3]: https://github.com/igerber/diff-diff/compare/v2.0.2...v2.0.3

CITATION.cff

@@ -7,8 +7,8 @@ authors:
     family-names: Gerber
     orcid: "https://orcid.org/0009-0009-3275-5591"
 license: MIT
-version: "3.1.0"
-date-released: "2026-04-14"
+version: "3.1.1"
+date-released: "2026-04-16"
 url: "https://github.com/igerber/diff-diff"
 repository-code: "https://github.com/igerber/diff-diff"
 keywords:

diff_diff/__init__.py

@@ -228,7 +228,7 @@
 ETWFE = WooldridgeDiD
 DCDH = ChaisemartinDHaultfoeuille
 
-__version__ = "3.1.0"
+__version__ = "3.1.1"
 __all__ = [
     # Estimators
     "DifferenceInDifferences",

docs/llms-full.txt

@@ -2,7 +2,7 @@
 
 > A Python library for Difference-in-Differences causal inference analysis. Provides sklearn-like estimators with statsmodels-style output for econometric analysis.
 
-- Version: 3.1.0
+- Version: 3.1.1
 - Repository: https://github.com/igerber/diff-diff
 - License: MIT
 - Dependencies: numpy, pandas, scipy (no statsmodels dependency)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "diff-diff"
-version = "3.1.0"
+version = "3.1.1"
 description = "Difference-in-Differences causal inference with sklearn-like API. Callaway-Sant'Anna, Synthetic DiD, Honest DiD, event studies, parallel trends."
 readme = "README.md"
 license = "MIT"

rust/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "diff_diff_rust"
-version = "3.1.0"
+version = "3.1.1"
 edition = "2021"
 rust-version = "1.84"
 description = "Rust backend for diff-diff DiD library"