This document discusses the concept of morphological productivity. It defines productivity as the ability of an affix or word formation rule to coin new words. Productivity can vary, with some affixes being highly productive and able to generate many new words, while others are unproductive. Productivity is constrained by both pragmatic factors like trends and structural factors like phonological or morphological restrictions on affixes. Measuring the productivity of an affix involves counting how many new words it has formed. Blocking also limits productivity, where an existing word blocks the formation of a similar derived word.