Source Preference in the Wild: How LLM Agents Favor Items by Source, and How to Reduce It

A study of end-to-end search with LLM agents finds that the agents develop a preference for items based on their source, shaping which products, hotels, or papers users receive and which sources get selected. The research examines how this source preference arises and how it can be reduced.

As LLM agents decide on users' behalf which product to buy, which hotel to book, or which paper to cite, a preference for items from certain sources the sites or services they come from shapes what users receive and which sources are selected. We study source preference in end-to-end search with 1