Anatomy of an Over-Merge — 235 River Avenue

◆ The over-merge, at a glance

I. The tie: one shared office

Every one of the 27 buildings files its head officer from the same back-office suite:

That's not a home address — it's a shared registration office (a Lakewood back-office used by dozens of unrelated landlords), with a full degree of 45 distinct owners across the city. It's the housing-data equivalent of a mailing-list address: presence there says nothing about who owns what. Yet a shared string is exactly what registration-contact graphs link on.

II. How Who Owns What over-merges

WoW builds a node per (owner name, business address) and draws edges two ways: same name, or same business address. Here the names are all different — and typo-split into 10 name slots — so the name edges don't span them. But the address is identical for all 27. That single shared-office edge is enough: connected components sweeps the whole set into one portfolio.

III. How Watchline corrects it

The correction is subtler than "delete the shared address." The office does wire these owners together in the graph — there are 55 CONNECTED_BY_ADDRESS edges among them, 51 of which cross owner boundaries. Watchline's owner-identity layer (OwnerGroup) simply declines every one of the 51:

IV. The mirror of Escobar

The same address-edge machinery fails in opposite directions, and Watchline's precision-first resolver fixes both:

V. Method & provenance

• The tie (raw HPD): all 27 buildings' head-officer contacts in hpd_contacts file from 235 River Ave #220, Lakewood NJ; that suite has a degree of 45 distinct owners.
• WoW's over-merge: wow_portfolios places all 27 in one portfolio, spanning 10 distinct name slots — linked purely by the shared business address.
• Watchline's split: grouping the 27 buildings' registered landlords by IN_OWNER_GROUP yields 7 owner units (5 owner groups + 2 singletons); the 51 cross-owner CONNECTED_BY_ADDRESS edges are declined.
• Explore: the interactive map — toggle Who Owns What's one portfolio ↔ Watchline's seven owners.

VI. See it in the graph (Cypher)

The exact subgraph behind this analysis, ready to paste into Neo4j Browser. The shared office isn't a KG node — it's the Landlord.bizaddr property behind the CONNECTED_BY_ADDRESS edges — so the query synthesizes a virtual :Office hub (in-memory, nothing written) and wires every landlord to it with a FILES_FROM edge. It returns the 27 buildings, their 11 landlords all MEMBER_OF one over-merged Portfolio, the shared-office web of CONNECTED_BY_ADDRESS edges, and the OwnerGroup split.

// === Miller over-merge subgraph + synthesized shared-office hub — 235 River Ave #220 ===
// The office is NOT a KG node (it's the Landlord.bizaddr property behind the
// CONNECTED_BY_ADDRESS edges), so we create a VIRTUAL :Office node and wire every
// landlord to it with a virtual FILES_FROM edge (in-memory; nothing is written).
WITH ['1004360028','1004360029','1004360129','1004370027','1019880024','1020700019',
      '2032780028','2032780054','2032790006','2032830022','2032890032','2032930142',
      '2032930144','2032930146','2033010063','3003050032','3003930043','3012680001',
      '3012820053','3027570036','3027890011','3032210031','3032370001','3050880046',
      '3051890045','3052150042','4031040070'] AS bbls
MATCH (b0:Building)<-[:REGISTERED_FOR]-(l0:Landlord) WHERE b0.bbl IN bbls
WITH bbls, collect(DISTINCT l0) AS lls
CALL apoc.create.vNode(['Office'], {name:'235 River Ave #220, Lakewood NJ', owners_on_file:45}) YIELD node AS office
UNWIND lls AS l
CALL apoc.create.vRelationship(l, 'FILES_FROM', {}, office) YIELD rel AS files
OPTIONAL MATCH (l)-[rf:REGISTERED_FOR]->(b:Building)          WHERE b.bbl IN bbls
OPTIONAL MATCH (l)-[inre:IN_OWNER_GROUP]->(re:OwnerGroup)
OPTIONAL MATCH (l)-[mem:MEMBER_OF]->(p:Portfolio)
OPTIONAL MATCH (l)-[conn:CONNECTED_BY_ADDRESS|CONNECTED_BY_NAME|CONNECTED_BY_SPLINK|CONNECTED_BY_DEED]-(l2:Landlord)
  WHERE l2 IN lls
RETURN office, files, l, rf, b, inre, re, mem, p, conn, l2

Renders ~44 nodes: 27 Building · 11 Landlord · 5 OwnerGroup (+ 2 unattached singletons) · 1 Portfolio · 1 virtual :Office. Colour relationships by type to see the CONNECTED_BY_ADDRESS tangle crossing the owner-group clusters.