diff --git a/assets/js/ga.js b/assets/js/ga.js
index a6b941c..b296bf3 100644
--- a/assets/js/ga.js
+++ b/assets/js/ga.js
@@ -2,11 +2,15 @@
    counted. Incoming utm_* (from shared links or other team sites) reach GA through page_location
    and are then removed from the address bar so the URL people copy stays clean. */
 (() => {
+  /* ID is the hub's GA4 stream. Google serves no tag script for that ID on its own (gtag/js?id=ID is a 404);
+     the stream's Google tag is TAG, so the script loads from TAG and only ID is configured, which keeps the
+     hub's events in the hub's property. */
   const ID = "G-C5V0X2SGD3";
+  const TAG = "G-BEBVKYH8HL";
   if (location.hostname === "causalinferencelab.github.io") {
     const s = document.createElement("script");
     s.async = true;
-    s.src = `https://www.googletagmanager.com/gtag/js?id=${ID}`;
+    s.src = `https://www.googletagmanager.com/gtag/js?id=${TAG}`;
     document.head.appendChild(s);
     window.dataLayer = window.dataLayer || [];
     window.gtag = function gtag() { window.dataLayer.push(arguments); };