Mariko Nakagawa Assistant Professor, Division of Spatial Socio-Economic Research (2016-)
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Ethnic segregation and spatially disproportionate distribution of skills

When analyzing residential distribution of various sorts of people in urban areas, differences in ethnic compositions, income levels, and population sizes of ethnic/income groups are considered as primal factors determining segregation patterns, all of which may vary over time. In order to take into account these time variant factors, spatial economic analyses of residential segregation based on dynamic models are needed. By employing these dynamic models, investigation of realistic situations such as the one in which minority population sizes change due to inflow of immigrants, the one in which the extent of ethnicity biases in terms of skill/income levels changes, and the one in which immigrants are gradually assimilated into a host country's society, becomes tractable.

Diversity/heterogeneity in language and economic development

Considering impacts on economic aspects of the society given by ethno-linguistic diversity has been attracting social attention not only in the international context but also in the urban or regional ones. Because diverse society is characterized by the variety of skills, productivity must be improved through skill complementarity borne by collaboration of different types of workers. Indeed, in cities or regions in advanced countries, this positive effect of ethno-linguistic diversity is observed. Turning to the researches on developing countries, however, heterogeneity in language appears to negatively affect economic development, partly because inefficiency caused by difficult communication between distant languages lessens productivity levels, and because political stability is hard to be kept. This project aims at empirically investigating whether diversity/heterogeneity in ethno-linguistic characteristics contributes to economic success, and if so, through which channel it does.

International migration models dealing with skill transferability and linguistic friction

Difference in language use causes problems that immigrants cannot fully utilize their skills due to language barriers. It is essentially important in the present time to consider whether they can smoothly transfer their human capital which has already been accumulated in their home country to the labor market in their destination, when commonly used languages are different between the origin and destination. Especially, in the case of high-skilled migration, skill transfer accompanied by friction of difference in language use is a crucial issue, because complex tasks that high-skilled workers are engaged in may require more sophisticated communication skills than manual ones. Since sharing common languages mitigates a burden of frictional costs stemming from language differences, it is highly valuable to jointly consider the skill transferability of high-skilled immigrants and the effect of widely used languages such as English. The objective of this project is to construct a spatial economic model of friction caused by differences in language use and skill transferability when international migration is taken place.