was realized. Various kinds of empirical studies have been initiated in Japan as well $ ^{Note 6} $ .

Figure 1-1-17 plots the results of a verification of the productivity effects of social capital using data from 1975 to 2009. A look at changes in the marginal productivity of social capital (a measure of to what extent production will increase when one additional unit of social capital is added) suggests that both private capital and social capital have diminished in marginal productivity in pace with the accumulation of capital but moved consistently with the onset of the 2000s. This is considered attributable to the effect of infrastructures that have been efficiently developed through cost-effective and other analyses since the beginning of the 2000s. Marginal productivity comparisons by social capital category indicate that social capital has high marginal productivity in those fields of transportation that presumably contribute directly to productive activities, such as roads, ports and harbors and airports. The extent to which infrastructures contribute to production is thus found to vary depending on characteristics of their categories.

Some prior studies attempted to verify the latter welfare effect. Figure 1-1-18 summarizes the results of verification of the welfare effects of social capital by using data classified by urban employment area $ ^{7} $ . Here, the welfare effect was verified in accordance with the concept of the capitalization hypothesis, whereby the benefit of an infrastructure developed in a given area is ascribed to the land rent (land price) as a result of increased demand for residential grounds in that area triggered by enhanced comfort and convenience. On the basis of the results of such verification, the marginal utility (a measure of to what extent the average land price will change when one unit of social capital is added) was calculated. According to information available from this website, if infrastructures are developed in a given

(Note) The 17 fields of social capital listed in "Japan's Social Capital 2012" by the Cabinet Office, less railways, public rental housing, water services, school facilities, agriculture, forestry and fisheries, postal services and industrial water, are used. Social capital falling under the jurisdiction of the MLIT covers the seven areas of roads, ports and harbors, airports, sewage systems, urban parks, flood control and seacoasts. Social capital relating to traffic covers the three fields of roads, ports and harbors and airports. Data from provisional calculation 3-2 has been used, in which patterns of diminishing efficiency of social capital (physical depletion, obsolescence and so on) have been set and the value of capital services derived from the future social capital estimated from these patterns has been converted to a present worth using a discount rate. For details on the estimation, see the Anotation 1.

Source) Developed by the MLIT from "National Accounts" and "Japan's Social Capital" by the Cabinet Office and from the "Japan Industrial Productivity (JIP) Database 2013" by The Research Institute of Economy, Trade and Industry (RIETI), an incorporated administrative agency and from others.

Livelihood and disaster preparedness social capital falling under the jurisdiction of the MLIT: Sewage systems, urban parks, flood control, seacoasts

Source) Developed by the MLIT from "Japan's Social Capital 2012" by the Cabinet Office, "Municipal Taxation Status Survey," "National Census" and "Housing and Land Statistics Survey" by Ministry of Internal Affairs and Communications (MIC) and "Prefectural Land Price Survey" and others by the MLIT.

area, the comfort and convenience of that area would be augmented and the effects of those infrastructures manifest