short alternatives for estimator names

diff_diff/__init__.py

@@ -159,6 +159,22 @@
     load_mpdta,
 )
 
+# ---------------------------------------------------------------------------
+# Short aliases – standard econometric abbreviations for interactive use.
+# The canonical (long) names remain the primary API; these are convenience
+# bindings so users can write e.g. ``from diff_diff import DiD``.
+# ---------------------------------------------------------------------------
+DiD = DifferenceInDifferences
+TWFE = TwoWayFixedEffects
+MPDiD = MultiPeriodDiD
+SDiD = SyntheticDiD
+CSA = CallawaySantAnna
+SA = SunAbraham
+IDiD = ImputationDiD
+TSDiD = TwoStageDiD
+DDD = TripleDifference
+Bacon = BaconDecomposition
+
 __version__ = "2.6.0"
 __all__ = [
     # Estimators
@@ -279,4 +295,15 @@
     "load_dataset",
     "list_datasets",
     "clear_cache",
+    # Short aliases (standard econometric abbreviations)
+    "DiD",
+    "TWFE",
+    "MPDiD",
+    "SDiD",
+    "CSA",
+    "SA",
+    "IDiD",
+    "TSDiD",
+    "DDD",
+    "Bacon",
 ]

tests/test_aliases.py

@@ -0,0 +1,61 @@
+"""Tests for short estimator aliases."""
+
+import diff_diff
+
+
+# Each (alias, canonical) pair to verify.
+_ALIAS_PAIRS = [
+    ("DiD", "DifferenceInDifferences"),
+    ("TWFE", "TwoWayFixedEffects"),
+    ("MPDiD", "MultiPeriodDiD"),
+    ("SDiD", "SyntheticDiD"),
+    ("CSA", "CallawaySantAnna"),
+    ("SA", "SunAbraham"),
+    ("IDiD", "ImputationDiD"),
+    ("TSDiD", "TwoStageDiD"),
+    ("DDD", "TripleDifference"),
+    ("Bacon", "BaconDecomposition"),
+]
+
+
+class TestAliases:
+    """Verify short aliases point to the same objects as the full names."""
+
+    def test_aliases_are_identical(self):
+        """Each alias must be the exact same object (``is``) as its canonical name."""
+        for alias, canonical in _ALIAS_PAIRS:
+            alias_obj = getattr(diff_diff, alias)
+            canonical_obj = getattr(diff_diff, canonical)
+            assert alias_obj is canonical_obj, (
+                f"{alias} is not the same object as {canonical}"
+            )
+
+    def test_aliases_in_all(self):
+        """All aliases must appear in ``__all__``."""
+        for alias, _ in _ALIAS_PAIRS:
+            assert alias in diff_diff.__all__, f"{alias} missing from __all__"
+
+    def test_canonical_names_in_all(self):
+        """Canonical names must still appear in ``__all__``."""
+        for _, canonical in _ALIAS_PAIRS:
+            assert canonical in diff_diff.__all__, (
+                f"{canonical} missing from __all__"
+            )
+
+    def test_alias_import(self):
+        """Aliases can be imported directly from the package."""
+        from diff_diff import (
+            DiD,
+            TWFE,
+            MPDiD,
+            SDiD,
+            CSA,
+            SA,
+            IDiD,
+            TSDiD,
+            DDD,
+            Bacon,
+        )
+        # Smoke-check: all are callable classes
+        for cls in (DiD, TWFE, MPDiD, SDiD, CSA, SA, IDiD, TSDiD, DDD, Bacon):
+            assert callable(cls)