Ethan Heffernan

This working paper quantifies how concentrated pharmaceutical revenues have become among the five largest U.S.-listed drug manufacturers—AbbVie, Bristol Myers Squibb, Johnson & Johnson, Merck, and Pfizer. Using public segment disclosures from 2022–2024, the study applies conventional concentration metrics (CR3, CR5, HHI) and introduces interval-bounded estimates to account for the opacity of aggregated "Other" revenue categories.

By treating undisclosed revenue segments as synthetic products, the approach yields upper and lower bounds for concentration that reflect both reporting heterogeneity and genuine economic exposure. Differences in disclosure practice alone can change perceived concentration risk by double-digit percentages — an important consideration for valuation, antitrust analysis, and portfolio risk assessment.

Financial Modeling World Cup (2025)

A fully integrated project finance DCF model of an EV charging station business, including detailed construction capex, equipment costs, operating cash flows, debt drawdown and amortization, and monthly projections from 2021–2030.

Self-directed project, 2025

A fully integrated project finance–style model of an e-commerce business, using marketing spend as the core investment driver. Includes monthly projections of ad spend, customer acquisition, orders, revenues, COGS, gross profit, operating expenses, and EBITDA, with scenario toggles and sensitivity structure.