Cartels are very difficult to detect. They can involve many companies in the sector and customers are rarely able to discover the existence of a cartel. Antitrust authorities should be helped to detect cartels through various means and instruments, the most effective leniency programs. These programs provide for immunity or reduction of penalties for cartel members who cooperate with competition authorities (or « whistleblowers »). Most OECD countries have adopted leniency programmes that have helped to increase the success rate in cartel detection. Vertical agreements are widely accepted because they are less likely to solve competition problems than horizontal agreements. Horizontal agreements are concluded between two current or potential competitors. However, vertical agreements may present competitive risks if .B potential to increase barriers to entry, reduce or mitigate competition, and avoid other opportunities in the event of horizontal agreements.  Under the category exemption and the Commission`s current guidelines, the above restrictions would normally be considered « pure. » The inclusion of a « hardcore » restriction automatically eliminates the potential benefits of safe port of the category exemption for the entire agreement. In addition, vertical agreements appear to be more effective in commercial activity. The most common vertical restrictions are: some vertical agreements probably contain restrictions that do not comply with Article 101 of the TFUE. These are agreements that contain provisions: ccess our new database of international agreements with more than 200 references since 2012 from some 50 countries.
A number of horizontal agreements between companies may not have a severe core cartel and, in some cases, have positive effects. For example, agreements between competitors in the fields of research and development, production and marketing can result in lower costs for companies or improved products whose benefits are passed on to consumers. The challenge for competition authorities is to assess these agreements and balance the pro-competitive effects with the anti-competitive effects that could distort the market. Prohibited horizontal cooperation can manifest itself as an explicit agreement between companies or a corresponding mutual agreement. Decisions or agreements in which corporate behaviour is effectively limited or controlled at the horizontal level are also prohibited. Such prohibited regulations may be .B.