What's in the Box? The Effect of Self-Preferencing on Amazon

Abstract

We examine product recommendations in Amazon’s “Similar items to consider” box in the US and Canada, finding evidence of self- preferencing in Canada. In our dataset, alternatives to Amazon Basics (AB) products are sometimes recommended in the US but never in Canada, while non-AB products are sometimes recommended in Canada but never in the US. By comparing sales across domains, we find that non-AB products not recommended in Canada due to self-preferencing experience a 22% sales decrease compared to those that are not exposed to self-preferencing in the same way.