[1] The panchronic program in phonology, however, is associated with the work of André-Georges Haudricourt, especially his seminal articles of 1940[2] and 1973,[3] and the preliminary synthesis published with Claude Hagège in 1978.
[4] Beyond case studies, one of the goals of comparative linguistics is to assemble data that lead to an inventory of the common types of sound change and to an improved understanding of the conditions under which they occur.
Panchronic laws are obtained by induction from a typological survey of precise diachronic events whose analysis brings out their common conditions of appearance.
It has been pointed out that the book La Phonologie panchronique, co-authored by Hagège and Haudricourt, only scratches the surface of the many topics that it aims to treat.
[5] In practice, the panchronic program requires the compilation of as many attested cases of sound changes as possible, with detailed information on the state of the linguistic system where it took place.
"[11] Martinet concludes: "I still would prefer calling this a working hypothesis rather than a panchronic law, because I am convinced we shall one day come across a language where the weakening of consonants will be found to result from some unforeseen complex of factors."
Even if every scholars agree that there exist competing phonetic tendencies, according to Labov (1994: 601) they do not have explanatory or predictive power when it comes to individual cases.