The Clayton Act addresses specific practices that the Sherman Act does not clearly prohibit, such as mergers and interlocking directorates (that is, the same person making business decisions for competing companies). Section 7 of the Clayton Act prohibits mergers and acquisitions where the effect "may be substantially to lessen competition, or to tend to create a monopoly." As amended by the Robinson-Patman Act of 1936, the Clayton Act also bans certain discriminatory prices, services, and allowances in dealings between merchants. The Clayton Act was amended again in 1976 by the Hart-Scott-Rodino Antitrust Improvements Act to require companies planning large mergers or acquisitions to notify the government of their plans in advance. The Clayton Act also authorizes private parties to sue for triple damages when they have been harmed by conduct that violates either the Sherman or Clayton Act and to obtain a court order prohibiting the anticompetitive practice in the future.

См.: https://www.ftc.gov/tips-advice/competition-guidance/guide-antitrust-laws/antitrust-laws

смысл " to substantially lessen competition"

см. http://www.law.cornell.edu/uscode/text/15/18

"....when the effect of such formation is not to substantially lessen competition.."

(перед этой фразой 2 раза идет формулировка из Вашего отрывка)

The term “may be substantially to lessen competition” indicates that Section 7 illegality is based on probable, rather than definite, anticompetitive effects.

https://www.antitrustinstitute.org/wp-content/uploads/2018/09/Section-7.pdf

+

http://clck.ru/TCNGd

кто-то когда-то скопировал с ошибкой и пошло...

в сети много документов с нормальной формулировкой - см. ссылку в пред. посте

см https://www.luc.edu/media/lucedu/law/students/publications/clr/pdfs/31-2/6-Steuer.pdf/

....Originally, the Clayton bill’s provision on acquisitions made it a crime to acquire another company where the effect “is” to “eliminate or substantially lessen competition” or “create a monopoly.” The Senate rejected the criminal approach and unanimously changed this language to “where the effect may be to lessen competition.” The conference committee reconciled the House and Senate versions by combining “may be” from the Senate version and “substantially” from the House version

Судя по Вашей ссылке, речь действительно идет о "существенном снижении" (там же встречаем the substantial lessening of competition ). Обстановка чуток проясняется.

Имелась в виду первая.

Вторая ссылка тоже хороша, но силы на сегодня исчерпаны.

"....For decades, two of the most knocked-around phrases in antitrust have been “may be substantially to lessen competition” and “tend to create a monopoly.” These tests—which reach anticompetitive harm in its incipiency—comprise the standard for judging mergers and acquisitions, as well as most exclusive dealing and tying, under the Clayton Act.5..."

http://pnu.edu.ru/ru/faculties/full_time/uf/iogip/study/studentsbooks/histsources2/ipgzio24/

"...может быть существенное ослабление конкуренции или же тенденция к образованию монополий ..."

Аплодирую автору текста. Он мог на нормальном человеческом языке это написать, но решил подколоть составителей документа и привел буквальную цитату. Мол, не бросайте в меня камни, это не я, а они так написали.

'may be substantially to lessen competition' is a less common way of saying 'may be to substantially lessen competition' -- but they mean the same.

The first construction (adverb+'to'+verb) doesn't involve splitting the 'to' and the verb in the infinitive, eg:

* 'gradually to discover that ......'

The second construction ('to'+adverb+verb) uses a so-called split infinitive because the adverb comes between the 'to' and the verb in the infinitive, eg:

* 'to gradually discover that ......'

Until the early 20th century split infinitives were considered by many English academics/purists to be grammatically incorrect. However, they're now accepted as the norm and are used in around 95% of cases. The second construction is now found mainly in very formal texts (eg some legal documents), in old literature, and by some modern authors who are writing in an ornate or 'historical' style.

Live and learn as they say )))

Correction @ 1:39, paragraph 3: "The second construction is now found mainly in ........" should read "The first construction is now found mainly in ........"

"снижение (уровня) конкуренции" - больше к новостям подходит

======================================

Закон Клейтона, 1914 г.

Статья 2. ... Признается незаконным, если любое лицо, занимающееся коммерцией, в ходе таковой коммерции прямо или косвенно осуществляет дискриминацию в ценах между различными покупателями товаров, которые продаются для использования, потребления или перепродажи в пределах Соединенных Штатов... или иного места, находящегося под юрисдикцией Соединенных Штатов, когда результатом такой дискриминации может быть существенное ослабление конкуренции или же тенденция к образованию монополий в любой сфере коммерческой деятельности.

https://pnu.edu.ru/ru/faculties/full_time/uf/iogip/study/studentsbooks/histsources2/ipgzio24/

Согласен. Ослабление конкуренции - более удачный вариант