The Reconciliation Layer: Reconciling Marketing Mix Model Estimates with Financial Actuals Karan Dhir

Abstract

Privacy rules, platform controls, and identifier loss have weakened user-level attribution. Marketing mix modeling (MMM) has therefore regained attention as a strategic measurement approach. Enterprise use can stall when model estimates meet financial reporting. In this case, the MMM estimates incremental net sales against a modeled counterfactual. Finance reports booked outcomes that may include accruals, reserves, allocations, and restatements. This paper develops and examines a Reconciliation Layer in an 18-month participatory case at a large U.S. biopharmaceutical enterprise. The layer has four parts: aligned definitions, a decomposition bridge with a disclosed residual, experimental checks, and governance tied to the financial calendar. The documentary record includes six quarterly release cycles, four governance versions, a 13-item defect register, and a reconciliation workbook covering 16 brands. The case identified four recurring reconciliation problems: source selection, timing, scope, and silent upstream changes. During implementation, the enterprise adopted an intake gate, a data-drop tracker, cutoff rules, and a bridge workbook. Finance also joined hierarchy mapping and long-term source-path work. These observations are descriptive. The case does not establish causal effects on allocation decisions or firm performance.