Just a quick one for today: Description and Explanation in Inflectional Morphophonology: The Case of the Japanese Verb, by Waseda professor Brente de Chene. I quote Professor de Chene's homepage:

Attempting to go beyond the question of what the descriptively adequate (psychologically real) analysis of the system [of Japanese verbal inflection] is to the question of the explanatory principles on the basis of which that analysis has been chosen over observationally adequate alternatives has led me to a reconsideration of the principles of base form (underlying representation) choice in phonology more generally.

Y'see, there's historically been debate over the underlying principles that drive the Japanese verb system. Specifically, when we see patterns like this (cut-down version of table from paper):

Inflection type	C-stem version	V-stem version
(root)	mat- ("wait")	mi- ("see")
Adnominal/predicative	mat-u	mi-ru
Passive	mat-are-	mi-rare-
Causative	mat-ase	mi-sase-

... One obvious hypothesis is that each inflection comes in a "long version" and a "short version":

Version	Examples	Begins with	Attaches to
Long	ru, rare, sase	Consonant	V-stem verbs
Short	u, are, ase	Vowel	C-stem verbs

... But the question then is, which is basic? Is the short version the basic form, with the initial consonant of the long version added simply to avoid hiatus? Or is the long version the basic form, with the short version created by deleting the consonant, or allowing it to assimilate (leaving no trace) to the consonant at the verb stem? Or is the "basic" form something else altogether, or different for each type of inflection, etc.?

Each point of view has had its champions in the past. What I like about de Chene's paper is that it offers a new approach to the problem that is based on and tested against actual data — the results of nationwide dialectical surveys — rather than the dreaded "armchair theorizing". It's long and quite technical, but very rewarding reading.