Fix binarized ATT description to reference group-time aggregation

Replace "simple mean difference" with "aggregating group-time effects"
in the binary comparison section, accurately reflecting the weighting
used by both ContinuousDiD and CallawaySantAnna.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: igerber

docs/tutorials/14_continuous_did.ipynb

@@ -563,13 +563,7 @@
    "cell_type": "markdown",
    "id": "a5230e69",
    "metadata": {},
-   "source": [
-    "## 7. Comparison to Binary DiD\n",
-    "\n",
-    "What if we ignore dose entirely and just run a standard binary Callaway-Sant'Anna estimator? Both approaches should give a similar **binarized ATT** (treated vs. untreated), but the binary approach discards all dose information — no dose-response curve, no marginal effects.\n",
-    "\n",
-    "Note: both estimators compute the binarized ATT as a simple mean difference (treated vs. untreated), so the values should be very close. Under standard PT this identifies ATT_loc (the local average); under strong PT it additionally equals ATT_glob. Any small differences arise from weighting or aggregation choices, control group or base period settings, or finite-sample variation — not from spline smoothing. The continuous approach provides the full dose-response curve on top of the binarized effect."
-   ]
+   "source": "## 7. Comparison to Binary DiD\n\nWhat if we ignore dose entirely and just run a standard binary Callaway-Sant'Anna estimator? Both approaches should give a similar **binarized ATT** (treated vs. untreated), but the binary approach discards all dose information — no dose-response curve, no marginal effects.\n\nNote: both estimators compute the binarized ATT by aggregating group-time effects, so the values should be very close. Under standard PT this identifies ATT_loc (the local average); under strong PT it additionally equals ATT_glob. Any small differences arise from weighting or aggregation choices, control group or base period settings, or finite-sample variation — not from spline smoothing. The continuous approach provides the full dose-response curve on top of the binarized effect."
   },
   {
    "cell_type": "code",
@@ -710,4 +704,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 5
-}
+}