welcome LOCAL CONSTRAINTS VS LOCAL ECONOMY 1

In Johnson and Lappin (1997) (J&L) we presented arguments against the incorporation of global economy conditions on derivations into the theory of grammar. The economy of derivation model of grammar proposed in Chapter 4 of Chomsky (1995b) postulates three such conditions: Procrastinate, The Shortest Derivation Principle (SDP), and the Have an Effect on Output Condition (HEOC). We showed that these conditions create serious problems of computational complexity and conceptual overhead which do not arise in a grammar that employs only local constraints on operations and representations. We argued that Procrastinate can be replaced by a strictly local constraint on Move, while the SDP and the HEOC can be discarded without loss of empirical coverage. We also compared a local constraint version of a derivational grammar satisfying minimalist assumptions concerning phrase structure and movement with a typed feature structure grammar that employs defeasible local constraints on feature unification and inheritance (a version of Pollard and Sag ‘s (1994) HPSG). We presented evidence from whstructures in Iraqi Arabic which strongly favours the typed feature structure model of grammar.