The main difference between horizontal collusion and vertical collusion lies in the relationship between the firms involved and their positions in the supply chain. Here's a detailed explanation of each type:

1. Horizontal Collusion

• Definition: Horizontal collusion occurs between firms operating at the same level of the supply chain, i.e., direct competitors in the same industry.
• Purpose: The primary aim is to reduce competition among these firms by coordinating strategies such as fixing prices, limiting output, or dividing markets.
• Examples of Horizontal Collusion:
  • Price Fixing: Competing airlines agree on ticket prices for certain routes.
  • Market Sharing: Cement manufacturers divide geographic regions to avoid competition.
  • Output Restriction: Oil companies in a cartel agree to cap production to influence prices.
• Legal Implications: Horizontal collusion is typically illegal in most jurisdictions because it undermines fair competition, leading to higher prices and reduced consumer choice.
  • Example: Antitrust laws like the Sherman Act in the U.S. or EU Competition Law prohibit horizontal collusion.
• Impact:
  • Negative for Consumers: Higher prices, less innovation, and fewer choices.
  • Positive for Colluding Firms: Higher joint profits and stability.

2. Vertical Collusion

• Definition: Vertical collusion occurs between firms operating at different levels of the supply chain, such as manufacturers, distributors, or retailers.
• Purpose: The objective is to coordinate actions across the supply chain to control market conditions, such as limiting resale prices, restricting supply, or excluding competitors.
• Examples of Vertical Collusion:
  • Resale Price Maintenance: A manufacturer forces retailers to sell a product at a minimum price, reducing retail competition.
  • Exclusive Dealing Agreements: A supplier colludes with distributors to prevent them from selling competitors' products.
  • Bid Rigging: A contractor and a subcontractor collude to manipulate procurement outcomes.
• Legal Implications: Vertical collusion is generally treated more leniently than horizontal collusion because it may sometimes improve supply chain efficiency. However, it is illegal if it significantly reduces competition or harms consumers.
  • Example: A manufacturer conspiring with retailers to fix prices can be challenged under antitrust laws.
• Impact:
  • Negative for Competition: Can create barriers for new entrants and reduce competition at certain levels of the supply chain.
  • Neutral or Positive for Consumers: Sometimes improves efficiency or ensures consistent product quality.