Colloquium: Prof. Hiroaki Matsuura

A tremendous amount of radioactive products was discharged as a result of the accident at the Fukushima nuclear power plant in March 2011, which resulted in radioactive contamination of the plant and surrounding areas. When describing the geographical distribution of radioactive contamination, the government, media, and other organizations largely used administrative boundaries (prefectures, municipalities etc.) or distance from the radiation source as a reference. I examine how this sometimes misleading information about risks, as opposed to the actual risks of radiation, significantly and negatively affected land prices and residential movement of Japanese and non-Japanese people in locations near the plant. I find that the prefecture border effects – but neither the distance effect from the nuclear power plant nor the effect of the actual risk of radiation – are significantly related to a reduction in land price and probability of moving into the area after the accident. This is to say that, even with the absence of the actual risk of radiation, the land price and population in Fukushima and its three adjacent prefectures has declined more rapidly than that in other prefectures of Japan after the accident. I also find that non-Japanese residents responded less to the prefecture border effects. Although health risk information based on prefecture has an obvious advantage of distilling large and complex risk information into a simple one, the government, media, and other organizations need to recognize and carefully examine the potential of misclassifying non-contaminated areas into contaminated prefectures. Doing so will avoid unintentional consequences to the region’s economy.