Dr. Sappenfield is an applied economist who specializes in questions of financial conduct, incentives, and value. His experience in these matters is often in the context of financial markets, technology-intensive firms, and big data.

He has led project teams in both consulting engagements and expert testimony, supporting experts from Brattle, academic institutions, and industry firms. These engagements include assessing market manipulation and round-trip trading in fixed income securities markets; determining the materiality of accounting and financial misrepresentations; evaluating collusive behavior among communications numbering in the millions; estimating the extent of contract breaches with respect to residential mortgage-backed securities; proving intent to coordinate criminal conduct and incite violence; tracing money laundering and sanctions evasion; and valuing firms in venture capital and 10b-5 litigation.

Clients on these engagements included the US Department of Justice, the US Federal Trade Commission, investor class actions, and firms in technology and pharmaceutical industries.

Prior to joining Brattle, Dr. Sappenfield received his Doctor of Business Administration at Harvard Business School. He previously conducted statistical and research consulting for universities and technology firms, as well as in support of expert witness testimony in educational equity litigation. He also taught secondary math in the Dallas Independent School District. He is a certified paralegal.


Harvard Business School
DBA in Technology and Operations Management

Boston University
BA in Political Science and BS in Business Administration