New approaches to investigating change in derivational productivity. Gender and internal factors in the development of ‑ity and ‑ness, 1600–1800.

<jats:p>We study the productivity of the suffixes ‑<jats:italic>ness</jats:italic> and ‑<jats:italic>ity</jats:italic> in seventeenth‑ and eighteenth-century letters in the <jats:italic>Corpora of Early English Correspondence</jats:italic>. We analyze the role of gender and five internal factors: etymology, the word class of the base, branching structure, semantics, and occurrence in possessive constructions. We develop statistical and visual methods that facilitate diachronic comparisons within factors and between competing suffixes; our basic measure is the proportion of types of interest out of all relevant types, and we utilize permutation testing to assess the statistical significance of our findings. Our results support and refine the earlier finding of a male-led increase in the productivity of ‑<jats:italic>ity</jats:italic> and provide new information on the interplay of gender and internal factors.</jats:p>