Scenario: Andrew, Bob, and Christine are attorneys who formed a law firm. They filed no documents with the Secretary of State or any other state office. They equally share the firm’s profits after paying all expenses and make all business and management decisions. Associate attorneys are paid a fixed salary, plus 25% of gross billings for any clients they bring to the firm. Senior attorneys are paid based upon the number of hours they bill plus an annual bonus if they bill more than 2,000 hours in a year. The senior attorney bonus pool is equal to 5% of firm profits, which is split equally by the number of qualifying senior attorneys each year. Andrew, Bob, and Christine agreed to bestow the title "non-equity partner" on senior attorneys even though senior attorneys have no management authority. The firm website and business cards for senior attorneys list their title as "partner."
Question: What type of business entity is the firm using to conduct business? Discuss.