Resumen
Opendata efforts have now become a global movement, and Japan intends to keep up with this global trend. Measures concerning open data have been undertaken since the Open Government Data Strategy was adopted in July 2012. As a result, all 47 Japanese prefectures had developed Web pages for their own open data by March in 2018. However, only 18.3% of municipalities had their open data released on the Internet. In this paper, we investigate how deeply opendata efforts have penetrated into local municipalities, not just the national average in Japan. By analyzing the opendata disparities, we then infer the factors that have facilitated opendata initiatives in local governments. We introduce an opendata penetration rate? for each prefecture, calculating it by using the number of municipalities that have already published their own open data, and we find that there is a regional disparity in the opendata efforts. By adding qualitative information to this quantitative research, we have found that there are three types of collaborations among the local governments that have already published open data. On the basis of these findings, we discuss which type of collaboration is the most promising for small-sized municipalities.