diff --git a/public/src/economy.js b/public/src/economy.js
index 6a92661..571f3f3 100644
--- a/public/src/economy.js
+++ b/public/src/economy.js
@@ -60,6 +60,24 @@ const LABEL_TO_RESOURCE = (() => {
 
 // ── Income calculation ────────────────────────────────────────────────────────
 
+/**
+ * Returns a multiplier based on planet population.
+ * Base factor = billions / 10, plus an efficiency boost for smaller populations:
+ *   0–10 B → ×10,  10–100 B → ×5,  100–1000 B → ×2.5,  >1000 B → ×1
+ *
+ * @param {number} billions
+ * @returns {number}
+ */
+function populationFactor(billions) {
+  const base = billions / 10;
+  let boost;
+  if (billions < 10)        boost = 10;
+  else if (billions < 100)  boost = 5;
+  else if (billions < 1000) boost = 2.5;
+  else                      boost = 1;
+  return base * boost;
+}
+
 /**
  * Compute income per second for a team based on their discovered planets.
  *
@@ -80,12 +98,13 @@ export function computeTeamIncome(team, cells, resourceWorth) {
     const { naturalResources } = meta.planet;
     if (!naturalResources) continue;
 
+    const popFactor = meta.planet.population ? populationFactor(meta.planet.population.billions) : 1;
     for (const [label, pct] of Object.entries(naturalResources)) {
       const info = LABEL_TO_RESOURCE.get(label);
       if (!info) continue;
       const worth = resourceWorth?.[info.cat]?.[info.key] ?? 0;
       if (worth === 0) continue;
-      const income = (pct / 100) * worth;
+      const income = (pct / 100) * worth * popFactor;
       byResource.set(label, (byResource.get(label) ?? 0) + income);
       total += income;
     }
@@ -109,13 +128,14 @@ export function computeTeamIncomeByPlanet(team, cells, resourceWorth) {
     if (!meta.hasPlanet || !meta.planet) continue;
     const { name, naturalResources } = meta.planet;
     if (!naturalResources) continue;
+    const popFactor = meta.planet.population ? populationFactor(meta.planet.population.billions) : 1;
     let income = 0;
     for (const [label, pct] of Object.entries(naturalResources)) {
       const info = LABEL_TO_RESOURCE.get(label);
       if (!info) continue;
       const worth = resourceWorth?.[info.cat]?.[info.key] ?? 0;
       if (worth === 0) continue;
-      income += (pct / 100) * worth;
+      income += (pct / 100) * worth * popFactor;
     }
     if (income > 0) rows.push({ name: name ?? "?", income });
   }