In Economy and Semantic Interpretation, Danny Fox investigates the relevance of principles of optimization (economy) to the interface between syntax and semantics. Supporting the view that grammar is restricted by economy considerations, Fox argues for various economy conditions that constrain the application of "covert" operations. Among other things, he argues that syntactic operations that do not affect phonology cannot apply unless they affect the semantic interpretation of a sentence. This position has a number of consequences for the architecture of grammar.
Recent developments in linguistic theory have led to a reconsideration of the role of optimality in the overall architecture of the grammar. Emerging from this research is the idea that different components of the grammar interact to yield the best choice from a set of candidate derivations.