diff --git a/docs/index.html b/docs/index.html index 872ee89..1bafaf3 100644 --- a/docs/index.html +++ b/docs/index.html @@ -31,7 +31,7 @@ .scene .text{flex:1.15;} .scene .panel{flex:1;} .scene .mk{font-size:13px;letter-spacing:.3em;text-transform:uppercase;color:var(--red);} - .scene .eq{margin:18px 0 22px;border-left:2px solid var(--red);padding:5px 0 5px 15px;color:#3a3f4a;font-size:19px;} + .scene .eq{margin:18px 0 22px;border-left:2px solid var(--red);padding:5px 0 5px 15px;color:var(--ink);font-size:19px;} .scene h2{font-family:var(--serif);font-weight:400;font-size:clamp(26px,3.6vw,40px);line-height:1.08;letter-spacing:-.015em;margin:0;} .scene h2 .ll{color:var(--red);font-style:italic;} .scene .supp{color:var(--muted);font-size:14px;line-height:1.6;margin-top:20px;max-width:46ch;} @@ -60,7 +60,7 @@ - +
Weighted Subgroup Analysis

Two subgroups,
pulled into balance.

@@ -69,46 +69,47 @@

Two subgroups,
pulled into balance.

-
+
01 · the setup
-

Many studies ask how an effect differs by subgroup.

-
Split the sample into G = 0 and G = 1, estimate the treatment effect in each, and compare.
+
+

Comparing an effect across subgroups.

+
Estimate the treatment effect within subgroup G = 0 and within subgroup G = 1, then compare them. A gap of Δ = 4 pp. Should we trust it?
-
+
02 · the problem
-
-

But G is tangled with other moderators M.

-
Is the effect different by G — or by what G is correlated with? The subgroups don't share the same distribution of M.
+
+

is tangled with other moderators .

+
Is the effect different by G, or by what G is correlated with? The subgroups don't share the same distribution of M.
-
+
03 · the idea

Up-weight the units that look like the other group.

-
— and down-weight the ones that look like their own. Estimate it from the propensity to belong to G = 1.
+
Conversely, down-weight the ones that look like their own. Estimate it from the propensity to belong to G = 1.
-
+
04 · balance
-

Now M is distributed identically across subgroups.

-
The remaining difference in effects is attributable to G, holding M constant.
+

Hold constant, and the true gap emerges.

+
With M balanced across subgroups, the effect gap is no longer masked: Δ′ = 9 pp, attributable to G.
-
+
05 · the honest caveat

Observable balance is necessary, not sufficient.

@@ -120,7 +121,7 @@

Observable balance is necessary, not sufficient.