Tort law (2022): Economic torts: Restraints of trade

Restraints of trade is a common law doctrine relating to the enforceability of contractual restrictions on freedom to conduct business. It is a precursor of modern competition law. In an old leading case of Mitchel v Reynolds (1711) Lord Smith LC said,

It is the privilege of a trader in a free country, in all matters not contrary to law, to regulate his own mode of carrying it on according to his own discretion and choice. If the law has regulated or restrained his mode of doing this, the law must be obeyed. But no power short of the general law ought to restrain his free discretion.

A contractual undertaking not to trade is void and unenforceable against the promisor as contrary to the public policy of promoting trade, unless the restraint of trade is reasonable to protect the interest of the purchaser of a business. Restraints of trade can also appear in post-termination restrictive covenants in employment contracts.

United States.

In the US, the first significant discussion occurred in the Sixth Circuit's opinion by Chief Judge (later US President and still later Supreme Court Chief Justice) William Howard Taft in United States v Addyston Pipe & Steel Company Judge Taft explained the Sherman Antitrust Act of 1890 as a statutory codification of the English common-law doctrine of restraint of trade, as explicated in such cases as Mitchel v Reynolds. The court distinguished between naked restraints of trade and those ancillary to the legitimate main purpose of a lawful contract and reasonably necessary to effectuation of that purpose. An example of the latter would be a non-competition clause associated with the lease or sale of a bakeshop, as in the Mitchel case. Such a contract should be tested by a "rule of reason," meaning that it should be deemed legitimate if "necessary and ancillary." An example of the naked type of restraint would be the price-fixing and bid-allocation agreements involved in the Addyston case. Taft said that "we do not think there is any question of reasonableness open to the courts to such a contract." The Supreme Court affirmed the judgment. During the following century, the Addyston Pipe opinion of Judge Taft has remained foundational in antitrust analysis.