The Productivity of Public Capital: Evidence from the 1994 Electoral Reform of Japan

This paper attempts to estimate the causal effect of public capital stock on production using Japanese prefectural data. We first articulate the difficulty of consistently estimating the regional-level production function with public capital due to the endogeneity of the public capital stock amount. As the central government allocates most of the public capital across regions in Japan, the stock amount of public capital could be endogenous because it could be allocated to either booming regions to support private activity or to stagnating regions to help them become more productive. The endogeneity of public capital is more serious when local governments make decisions regarding public capital investments, as in the US, because such decisions are directly affected by local governments' budgetary constraints. We need an exogenous variation of public capital investment across regions in order to estimate the causal effect of public capital on production. Japan's electoral reform in 1994 offers an exogenous variation of this sort. The reform drastically changed the distribution of political representation in the Lower House across regions, and it accordingly changed the allocation of public capital across regions as well. The productivity of public capital based on this natural experimental identification strategy indicates higher productivity due to public capital than indicated by the OLS estimation

Cutaneous wound healing promoted by topical administration of heat-killed Lactobacillus plantarum KB131 and possible contribution of CARD9-mediated signaling

Abstract Optimal conditions for wound healing require a smooth transition from the early stage of inflammation to proliferation, and during this time alternatively activated (M2) macrophages play a central role. Recently, heat-killed lactic acid bacteria (LAB), such as Lactobacillus plantarum (L. plantarum) have been reported as possible modulators affecting the immune responses in wound healing. However, how signaling molecules regulate this process after the administration of heat-killed LAB remains unclear. In this study, we examined the effect of heat-killed L. plantarum KB131 (KB131) administration on wound healing and the contribution of CARD9, which is an essential signaling adaptor molecule for NF-kB activation upon triggering through C-type lectin receptors, in the effects of this bacterium. We analyzed wound closure, histological findings, and inflammatory responses. We found that administration of KB131 accelerated wound closure, re-epithelialization, granulation area, CD31-positive vessels, and α-SMA-positive myofibroblast accumulated area, as well as the local infiltration of leukocytes. In particular, M2 macrophages were increased, in parallel with CCL5 synthesis. The acceleration of wound healing responses by KB131 was canceled in CARD9-knockout mice. These results indicate that the topical administration of KB131 accelerates wound healing, accompanying increased M2 macrophages, which suggests that CARD9 may be involved in these responses