Effects of mobility on dialect change: Introducing the Linguistic Mobility Index

Abstract

The more we are exposed to other speakers’ dialects, the larger their potential effect on our own dialect. This paper introduces a method which quantifies individuals’ linguistic exposure to other dialects through mobility, thus contributing a tool to the study of language variation and change. Throughout the last century, increasing mobility of society (e.g. longer-distance commuting; relocating to distant locations for work, study or marriage) has caused linguistic connections to become much more diverse, contributing to an acceleration of dialect change. To assess the impact of individual mobility on this change, we propose the Linguistic Mobility Index (LMI), which estimates long-term exposure to dialectal variation based on episodes of linguistic biography that can be extracted from dialect survey metadata. The LMI was conceptualised based on the Swiss German Dialects Across Time and Space (SDATS) corpus. Four LMI variants were constructed, comprising combinations of influencing factors, such as parents’ dialects, long-term partners, places lived in German-speaking regions, place of work and ongoing education. The factors are combined in a weighted manner, according to the relation with and exposure to the factor. The LMI variants employ different theoretical considerations and the combinations of influencing factors included in them simulate the availability of metadata in other studies. Using mixed-effects modelling, we evaluate the utility of the LMI variants as predictors of dialect change between historic and contemporary speech data of Swiss German. All of the LMI variants successfully show that higher exposure to dialectal variation (typically due to geographical mobility) contributes to more dialect change. This success in establishing LMI variants with different compositions as meaningful predictors allows us to claim that similar indices could be constructed for other language variation and change studies.