The test
The question was simple and the industry keeps avoiding it: does it matter whether vernacular creative is translated from an English master or developed natively in the language? We held media weight, channel mix, flight and audience constant and varied only the creative development route.
Same money, same schedule, same target. The natively developed executions delivered 2.1 times the effectiveness on our composite measure of prompted recall, message association and stated consideration shift.
Why the gap is that large
Translation preserves denotation and loses almost everything else. Idiom, rhythm, humour, the specific cadence that signals this was made for you rather than adapted at you — none of it survives a translation brief, and audiences detect the difference immediately even when they cannot articulate it.
There is also a casting and production dimension. Natively developed work tends to be cast, directed and scored for the language it lives in. Translated work is usually a voice replacement over visuals conceived elsewhere, and the mismatch reads as inauthenticity.
The budget objection
The standard objection is cost: developing natively in multiple languages costs more than translating one master. That is true at the production line item and false at the campaign level. A 2.1x effectiveness delta on the media investment dwarfs the incremental production cost in every scenario we have modelled.
If the budget genuinely cannot stretch to native development across every language, develop natively in the two or three languages carrying the most weight and translate the tail. Do not spread a translation thinly across nine languages and call it a vernacular strategy.