Thomson Reuters

Thomson Reuters Corporation sells legal research (Westlaw), news (Reuters), and tax and accounting tools. In the United States, Westlaw and Lexis are the two systems most law firms treat as non-optional.

Case law itself is public. The headnotes, citation graphs, and search that make it usable are private. A firm that has built workflows, folders, and briefs on one system faces a real switching cost. That is data lock-in in a two-firm market.

The company has bought legal-tech and tax tools that sit beside research. Each deal can remove a startup that was the independent layer on top of both Westlaw and Lexis. Merger policy here is about the tools around the database, not about owning the court opinions.

Reuters news and data terminals compete with Bloomberg in a similarly concentrated professional market. Exclusive data sets — unique identifiers, contributor prices — are the input rivals say they cannot replicate.

Legal research is a duopoly for practical purposes. Workflow lock-in keeps it that way.

Acquisitions of analytics and brief-drafting tools extend the duopoly into the software around the cases.

Citation systems that courts and journals require are a standard-setting advantage.

Terminal data exclusives are the news-side version of the same bottleneck.

Clients pay for Westlaw inside legal bills. They do not choose the research system.

A small firm priced out of both major systems uses thinner tools and is at a research disadvantage, which is a market-access issue for the profession.