Most recent measures of morphological productivity are reliable only if they are based on a large corpus of the language. This article presents a detailed demonstration of a method for establishing an inventory of productive affixes in a language for which a large corpus is not available. This method evaluates the productivity of an affix first and foremost on the basis of its threshold of profitability (the number of different words derived via the affix) in correlation with other diagnostics to bolster reliability. These other diagnostics are the semantic and phonological transparency of derived words and the decomposability of such words. The application of the method is illustrated step-by-step with data from St. Lucian.
