A method and system for determining topical authority may include receiving topic information for a document, the information including at least one topic and a weight for each topic, where the topic relates to content of the document, and the weight represents how strongly the topic is associated with the document. Authorship information for the document may be received, the information including, for each topic in the document, at least one author and an authorship percentage for each author. An update to an authority signature value for a first author of a first topic may be generated based on a product of an authorship percentage for the first author of the first topic and the weight of the first topic in the document, where the first topic is included in the received topic information.