Accounting is sometimes derided for being more of an art than a science. Law firm accounting can be even more creative.

Firms can easily manipulate their average profits per equity partner by limiting the number of full equity partners and by including or excluding partners who left midyear, depending on what helps their figure most. And revenue growth offers little insight as to whether a firm has won more premium mandates, hired in more partners or simply received a large payment for a long-running piece of work.