Chapter 5 THE BALANCE BET\ru'EEN STORAGE AND COMPUTATION IN PHONOLOGY Geert Booij Abstract This article cliscusses trvo kinds of phorrological evidence concerning the balarrce I;etween storage arrd cornputation: allomorphy and phonolog- ical changi:. It is shorvn that even allotnorphs that carr be derived by a prociuctive phorrological rule are sometimes stored irr lexical uremory because these allomorphs are preserved although thc relevant phono- Iogica,l process has beerr lost. Phonological processes that are sub.ject to lexical diffusion also requirc lexical storage of thc effects of these processes. This implics that the notions 'urrderlying fbrm' and 'lexi- cally storr:d Íbrrn' should not be equated: surface forrls are stored, and undcrlying Íbrms are cornputed whcn they are rreeded Íbr coining ne*, words. Keywords: Allornorphv, Auslautverhaeltung, final devoicing, lexical diffusiorr, Opti- rn:rlity Thcory, paradigrnatic leveling, phonological change, rrlc opacitv, underlying fblrn, vo.,vel Iengthening, vorvel reduction. 1. Introduction TIic r,lorninant view in ciassical generative phonology with respcct to the kind of phonological information that is stored in the lexicon, can be surrlnrarizcd as follows: what carr be cornputcd should not bc stored (cÍ'. Kcrrstowícz, 1994, p.60). This view implies that predictu,ble inlbrniatiorr about words is ornitted from lexical representatiorrs. In case thclc are alternatiorrs in the shape of rnorphemes, the prefcrred solutiorr is to assutne orre urld€rrlying folni for all alternants, Iisted in the lexicon, and to rlerivc the clifferent surÍace allonrorphs by means of onc or more phonological rules. This kincl of lexicon can be characterized as thc Bloomfir:ldiarr lexicon, since BIoomÍield, 1933. p.274 deíinecl thc lexicon as "a list of basic irrcgularities" " r33 S. Nooteboom et al. (eds.), Sbrage and Computatíon in the lnnguuge Far:utty, 133-.156. (c) 2002 KLtuver Ar:ude nit: PuhLishers. Printed in the NetherLands.