Coding efficiency in nominal inflection: expectedness and type frequency effects

Since (Zipf, George Kingsley. 1935. The psychobiology of language: An introduction to dynamic philology. Cambridge, MA: MIT Press; Zipf, George Kingsley. 1949. Human behavior and the principle of least effort. Journal of Consulting Psychology 13(3)), it has been known that more frequent lexical items tend to be shorter than less frequent ones, and this association between the length of an expression and its frequency has been applied to various grammatical patterns (syntactic, morphological, and phonological) and related to predictability or expectedness in the typological literature. However, the exact interactions of frequency and expectedness, their effect on shortening, and the mechanisms involved, are still not well understood. This paper proposes the Form-Expectedness Correspondence Hypothesis (fech), taking into account not only the frequency of expressions but their overall structure and distribution, and explores the fech in the domain of nominal inflection from a quantitative perspective.