This paper looks at how vertical mergers between companies can affect competition. The researchers found that when a company merges with another company in a different part of the supply chain, it can lower competition in the market. This happens because the merged company doesn't have to compete as hard for supplies, so it ends up keeping prices higher. This can lead to a pattern where all companies in the supply chain end up merging to avoid tough competition. The study shows that this type of anticompetitive behavior is more likely to happen when there is already strong competition among the companies selling the final products.