Gravity model of diffusion for Tokyo new dialect forms

In this paper it will be advocated that a simplified gravity model is applicable to linguistic change (lexical change) in progress. New dialect forms are born and are spreading all over Japan even in this age of standardization. “Tokyo new dialect” exhibits new dialectal forms recently introduced among young people in Tokyo. A new kind of database of geographical distribution of the Tokyo new dialect forms has been constructed.

The result shows an inverse correlation between usage rate and distance from Tokyo. After making a congregate map, a correspondence analysis was applied and the whole pattern of geographical distribution was analyzed. The large city of Osaka has shown a great influence on this Tokyo new dialect. Thus, it is clear that the “geographical proximity effect” has basically influenced the quantity of words introduced into Tokyo. The whole picture is clearly explained when population density is also taken into consideration, and when the simplified gravity model of geographical diffusion is applied.
All the processes of geographical diffusion to and from Tokyo fit with the “umbrella model” of diffusion which is proposed for new dialect formation and standardization in Japan. This umbrella model should be applicable to many languages of the world.