Closed conference. This type of liner conference restricts membership in order to protect the members’ market share. It is the most common type of conference.
This type of conference is frequently criticized because it is seen as being against free markets and “laissez faire”. The criticism also leads to allegations that the closed conference is not open to scrutiny and competition and can thus become a monopoly. In the United States the closed conferences were prohibited under severe penalties under the U.S. Shipping Act 1916. The closed conferences also fix the shares of the members and this can tend to remove incentives to improve service.