The consensus among policy makers on the perils of using standard patents as competitive weapons continues to build.

The Justice Department and the Patent and Trademark Office issued an unusual joint statement on Tuesday. Their move came after the Federal Trade Commission took an enforcement action last Thursday, as it closed its antitrust investigation of Google.

The focus is on the patents that cover basic communications and data-handling in the booming smartphone and tablet markets. They are known as standard-essential patents (or standards-essential patents, by those fond of an extra plural). Companies have voluntarily pledged to grant licenses to such patents to other companies on so-called fair, reasonable and nondiscriminatory terms, or FRAND licenses.

Companies do not make those pledges to technical standards organizations out of generosity, but from self-interest. They are creating a commercial commons of basic technology that everyone in the industry can build upon to enlarge a business like smartphones. For the licensor, the high volume of contracts on standard patents can make them solid, steady moneymakers.

The problem arises when in a market like smartphones, the temptation to bait and switch becomes great. The patent holder ignores its corporate promise, and tries to charge a rival an outlandish price for a license or takes the competitor to court, suing for infringement and seeking an injunction to stop the competitor’s shipments.

“The owner of that patented technology,” the agencies’ joint statement said, “may gain market power and potentially take advantage of it by engaging in patent holdup.”

The mere threat of a commercially devastating halt order on product shipments drives up the cost of patent licensing, and thus of mobile devices. It also makes companies less eager to cooperate on technology standards. That harms consumers and the innovation process, the Justice-Patent Office statement observed.

The joint statement was sent to Irving A. Williamson, chairman of the United States International Trade Commission, a quasi-judicial federal agency. The commission has the power to stop product shipments to the American market of devices that infringe on another company’s patents. The 10-page policy statement urges that with a few exceptions, the commission not order injunctions in cases involving standard patents.

The approach taken by the trade commission in such cases, the statement said, “will be important to the continued vitality of the voluntary consensus standards-setting process and thus to competitive conditions and consumers in the United States.”