In terms of legislative texts or guidelines, typically you add language to the efficiencies defence to say that the party invoking the efficiencies defence must show that the efficiencies flow through to the consumers—at least in a reasonable part. Then the authority has the tools to ask, “You're going to save 10% on your costs with this merger. How much of this is going to be passed through to the consumer?” That's the type of provision that you need.
On June 3rd, 2024. See this statement in context.