Abstract
<jats:p>Diachronic typology is an approach by which the patterns of language change are identified and characterized on a broad crosslinguistic scale. The study of diachronic universals is concerned with identifying common paths for these changes and understanding and explaining them in terms of the influences that shape them. Diachronic paths or trajectories can be identified on the basis of implicational universals in synchronic patterns, as well as synchronic variation. A number of conceptual and methodological issues arise in studying diachronic universals, including the relationship between synchronic variation and diachronic change, problems with characterizing various properties of paths, and what constitutes support for result‐oriented and source‐oriented accounts for the explanation of synchronic patterns. Methods and models proposed for studying diachronic universals are discussed, as well as a systematic approach to investigating diachronic influences on language universals. The use of this framework is demonstrated with a large‐scale crosslinguistic case study of ejective consonants which explores properties of sound change pathways resulting in ejectives, including their crosslinguistic frequencies, sources, and stages, the stability of ejective consonants, and the diffusibility of ejectives through contact.</jats:p>