diff --git a/.gitignore b/.gitignore
index 496ee2c..175f857 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
-.DS_Store
\ No newline at end of file
+.DS_Store
+deduplicatedLeads.json
\ No newline at end of file
diff --git a/index.js b/index.js
index d51a185..19b7ecf 100644
--- a/index.js
+++ b/index.js
@@ -10,6 +10,7 @@ const collisions = [];
 
 for (const currentLead of leads) {
   const { _id, email } = currentLead;
+
   const collidingLeadIdByEmail = leadIdssByEmail[email];
   const collidingLead = collidingLeadIdByEmail
     ? leadsById[collidingLeadIdByEmail]
@@ -28,20 +29,39 @@ for (const currentLead of leads) {
       // existing lead is newer than current lead
       // discard current lead by doing nothing with it
       collision.took = "left";
+
+      const discardedValues = [...(collision.right.discardedValues || [])];
+      delete collision.right.discardedValues;
+      discardedValues.push(collision.right);
+      const lead = {
+        ...collidingLead,
+        discardedValues,
+      };
+      leadsById[lead._id] = lead;
     } else {
       // current lead is newer than existing lead, or both leads have the same date
       // either way, take the current lead over the existing one
       collision.took = "right";
+
+      const discardedValues = [...(collision.left.discardedValues || [])];
+      delete collision.left.discardedValues;
+      discardedValues.push(collision.left);
+      const lead = {
+        ...currentLead,
+        discardedValues,
+      };
+
+      // rewrite indices by which field collides
       if (collision.collidingField === "_id") {
         // colliding ID - replace ID index, delete old email in email index
         delete leadIdssByEmail[collision.left.email];
         leadIdssByEmail[email] = _id;
-        leadsById[_id] = currentLead;
+        leadsById[_id] = lead;
       } else {
         // colliding email - replace ID in email index, delete old ID index
         leadIdssByEmail[email] = _id;
         delete leadsById[collision.left._id];
-        leadsById[_id] = currentLead;
+        leadsById[_id] = lead;
       }
     }
   } else {
@@ -51,9 +71,13 @@ for (const currentLead of leads) {
   }
 }
 
-console.log("collisions", collisions);
-console.log("leadsById", leadsById);
+fs.writeFileSync(
+  "./deduplicatedLeads.json",
+  JSON.stringify(Object.values(leadsById), null, 2)
+);
 
-console.log('records processed:', leads.length)
-console.log('collisions:', collisions.length)
-console.log('output leads:', Object.keys(leadsById).length)
\ No newline at end of file
+console.log("records processed:", leads.length);
+console.log("collisions:", collisions.length);
+console.log("output leads:", Object.keys(leadsById).length);
+
+console.log("collisions", collisions);