Clayton Act

The Clayton Act is a law of the United States dating from 1914. It belongs to what is known as antitrust law, meaning the set of rules intended to prevent a single company from controlling an entire market. The underlying idea: if there is only one provider left, it can dictate prices and no longer needs to make an effort. The Clayton Act therefore lists certain business practices and declares them illegal as soon as they substantially lessen competition. It remains in force to this day and has been amended several times. In the US, alongside the older Sherman Act of 1890, it is the most important tool against monopolies.

Why a law from 1914 affects tech companies today

The Clayton Act was created at a time when oil, steel, and railroad conglomerates dominated entire industries. Its older predecessor, the Sherman Act, only intervened once a monopoly already existed. The Clayton Act was meant to act earlier and stop developments that were foreseeably heading toward a monopoly. It is precisely this preventive character that makes it so important today.

That’s because technology markets often tip quickly toward a single winner. Whoever has the most users automatically becomes more attractive to new users. Examples include search engines, app stores, or social networks. If such a provider then also buys up its up-and-coming competitors, a market power emerges that can hardly be challenged anymore.

With artificial intelligence, the same question arises anew. Building large AI models costs billions and requires specialized chips that only a few companies manufacture. Competition authorities therefore closely monitor who is partnering with whom in this field. The Clayton Act provides the legal basis for examining such entanglements.

What the law specifically prohibits

The best-known part is Section 7. It prohibits mergers and corporate acquisitions if they could substantially lessen competition. The key word is “could”: no harm needs to have occurred yet, a reasonable probability is enough. Authorities can thus block an acquisition before it is completed.

Further sections target tying arrangements. This refers to a provider selling a desired product only if the customer also takes a second product along with it. Also prohibited are certain price differences that disadvantage small retailers compared to large ones. And a separate section prohibits the same person from simultaneously sitting on the boards of two competing companies.

The law is enforced by two agencies: the Federal Trade Commission and the Antitrust Division of the Department of Justice. They file lawsuits in court, which then decides. Unlike in European law, there is no agency that can simply prohibit a merger by administrative order. In addition, injured companies themselves can also sue and demand triple damages.

The term in business news

The Clayton Act regularly appears in reports about planned acquisitions. A typical phrasing is that an authority is reviewing a merger “under Section 7.” This simply means: it is being examined whether competition suffers as a result of the deal. Such proceedings can drag on for years and block a purchase price in the billions.

A common misconception is that size alone is prohibited. This is not the case. A company is allowed to become dominant in the market if it simply has the better product. What is prohibited is the path via acquisitions and restrictive contracts that block others' access to the market. This distinction is at the core of almost every antitrust case.

For European readers, some context is useful. The EU regulates similar matters through its own competition rules and the Digital Markets Act. However, because the major platforms are mostly US companies, an American court often has a say as well — relying on a law that is over a hundred years old.