Joël Berger

Who they are

Berger works on field experiments, cooperation and replication in the social sciences.

His 2017 paper in PLOS ONE did three things at once. It reran variations of the earlier luxury-label design under a double-blind procedure, so that nobody delivering the treatment knew the condition. It added a "green" label condition, testing for the first time in a natural field setting whether signalling theory also explains pro-environmental behaviour. And it ran in both average and below-average socioeconomic neighbourhoods, where the theory predicts luxury signals should be stronger.

The result was null on the luxury label across all five experiments, null on the green label, and in poorer neighbourhoods there was a negative tendency, with the label appearing to cost the wearer.

He is not Jonah Berger, the marketing professor who appears elsewhere on this site on word of mouth.

Key papers

Berger, J. (2017). "Are luxury brand labels and 'green' labels costly signals of social status? An extended replication." PLOS ONE, 12(2), e0170216. Sole author. Open access.

Key ideas

Blinding is not a technicality. It is the procedural detail most readers of either paper would skip, and the two results differ across it.

But more than one thing changed. He altered the procedure, added conditions and changed the neighbourhoods and population, so the honest conclusion is that the original did not survive a better-controlled attempt, not that blinding alone accounts for the difference. This record will not isolate one of three changes as the cause.

The observer matters. His own conclusion is that a signalling account has to take the characteristics of those watching into account, including their social status. See Costly Signalling.

---