Complexity of Scrambling: A New Twist to the Competence - Performance   Distinction
  In this paper we discuss the following issue: How do we decide whether a certain property of language is a competence property or a performance property? Our claim is that the answer to this question is not given a-priori. The answer depends on the formal devices (formal grammars and machines) available to us for describing language. We discuss this issue in the context of the complexity of processing of center embedding (of relative clauses in English) and scrambling (in German, for example) from arbitrary depths of embedding. 
Aravind K Joshi (University of Pennsylvania)