Copying vs. structure sharing a semantic argument

The term Focus Dependency describes an important phenomenon at the syntax-semantics interface: Elided material can exhibit bound-variable-like behavior when its antecedent is a focussed phrase in the same sentence. In the past, focus dependency has been analyzed as actual binding or by means of copying. This paper presents a new account of focus dependency that relies on the syntactic idea of structure-sharing. Structure-sharing allows sub-phrases to be syntactically linked to more than one position of a phrase marker. The proposal better explains focus dependency than existing accounts considering data from sentence-boundedness, insensitivity to c-command, extraction from the focus-dependent material, and the formal link to the antecedent. It also achieves a theoretical unification with other phenomena where structure sharing has been made use of, specifically movement.