The Public Financial System in Japan - Re-verification of the ballooning theory and the privileged government enterprise theory

The large weight of public financial institutions is often identified as one of the characteristics of the Japanese financial system. It is believed that reform of the private financial sector is not enough to revitalize the Japanese financial system, but reform of the public financial sector is crucial. There are various opinions concerning ideal public financial institutions, and heated debate continues. We would like to raise attention to the point that much discourse is based on the prerequisite that public financial sector is still increasing (i.e., the ballooning theory). However, only a small number of arguments present grounds for the prerequisite, and even in the case of those based on statistical analyses, such analyses are not rigorously verified. Under these circumstances, the first purpose of this paper is to reverify the ballooning theory of public financial sector which is used as a prerequisite for much of the discourse. Of course, although the ballooning theory may be overstated, private financial institutions cries for help strongly suggest that they are being squeezed by public institutions. The reason why public financial institutions that should be tightly regulated have such great power and oppress the private sector, which has been significantly deregulated in recent years, is often thought to be because so many privileges are given to public financial institutions as government enterprises (the privileged government enterprise theory). We agree that government enterprises have privileges, but if these are small, it is difficult to say that they are the main cause of the competitive dominance of government enterprises. The size of the privileges must be quantified to assess the privileged government enterprise theory. This is the second purpose of this paper. The following are the major conclusions of this paper. Concerning the public financial sector ballooning theory, various indexes prove that public financial activities had increased in share by around 1998, so from this aspect the ballooning theory is correct. However, this situation changed and since 1998 public financialactivities have either remained at the same level or have tended to decline. Further attention should be paid to the fact that when examining the relative size of public financial activities, the result varies significantly depending on how the area of interest is set. For instance, if finance is viewed as a risk bearing mechanism rather than a flow of funds, public involvement in finance in the U.S. may be greater than in Japan. Concerning the privileged government enterprise theory, it is true that Japan Post has privileges (e.g., the exemption of taxes as current expenses), but the estimate of 4.6 trillion over ten years by the Japanese Bankers Association is considered to be excessive. It may be judged that most of the privileges of the government enterprise have been eliminated during the establishment process of Japan Post and the conditions of government enterprise for competition are almost equalized with the private sector, On the other hand, government enterprise may become unable to bear the burden caused by restrictions imposed on them any longer (particularly the obligation of maintaining offices in remote areas), so how Japan Post can bear the burden must be considered. This paper is organized as follows. Section II examines the ballooning of the public financial sector, which is treated as the starting point of the debate concerning the reform of public financial system in Japan. Section III reverifies the privileges enjoyed by government enterprises. Section IV presents the conclusions of this paper.Public Financial System, Japan, ballooning theory, enterprise theory

Null-Brane Solutions in Supergravities

We find a new class of time-dependent brane solutions in supergravities in arbitrary dimensions $D$. These are general intersecting light-like branes (null-branes), and their superposition and intersection rules are obtained. This is achieved by directly solving bosonic field equations for supergravity coupled to a dilaton and antisymmetric tensor fields. We discuss their possible significance.Comment: 12 pages, v2: minor corrections, refs. added, v3: expressions of the solutions modifie

A Study of Accelerating Cosmologies from Superstring/M theories

We study aspects of the accelerating cosmologies obtained from the compactification of vacuum solution and S2-branes of superstring/M theories. Parameter dependence of the resulting expansion of our universe and internal space is examined for all cases. We find that accelerating expansions are obtained also from spherical internal spaces, albeit the solution enters into contracting phase eventually. The relation between the models of SM2- and SD2-branes are also discussed, and a potential problem with SD2-brane model is noted.Comment: 20 pages, 17 figures, a typo corrected, to be published in Prog. Theor. Phy

Cosmological model from the holographic equipartition law with a modified R\'{e}nyi entropy

Cosmological equations were recently derived by Padmanabhan from the expansion of cosmic space due to the difference between the degrees of freedom on the surface and in the bulk in a region of space. In this study, a modified R\'{e}nyi entropy is applied to Padmanabhan's `holographic equipartition law', by regarding the Bekenstein--Hawking entropy as a nonextensive Tsallis entropy and using a logarithmic formula of the original R\'{e}nyi entropy. Consequently, the acceleration equation including an extra driving term (such as a time-varying cosmological term) can be derived in a homogeneous, isotropic, and spatially flat universe. When a specific condition is mathematically satisfied, the extra driving term is found to be constant-like as if it is a cosmological constant. Interestingly, the order of the constant-like term is naturally consistent with the order of the cosmological constant measured by observations, because the specific condition constrains the value of the constant-like term.Comment: Final version accepted for publication in EPJC. The titile is revised and references are added. [12 pages, 4 figures

Introduction to branes and M-theory for relativists and cosmologists

We review the recent developments in superstrings. We start with a brief summary of various consistent superstring theories and discuss T-duality which necessarily leads to the presence of D-branes. The properties of D-branes are summarized and we discuss how these suggest the existence of 11-dimensional quantum theory, M-theory, which is believed to give rise to various superstrings as perturbative expansions around particular backgrounds in the theory. We also discuss the interpretation of brane solutions as black holes in string theories and statistical explanation of Bekenstein-Hawking entropy. The idea behind this interpretation is that there is a fundamental duality between closed (gravity) and open (gauge theory) string degrees of freedom, one of whose manifestation is what is kown as AdS/CFT correspondence. The idea is used to discuss the greybody factors for BTZ black holes. Finally the entropy of various balck holes are discussed in connection with Cardy-Verlinde formula.Comment: 28 pages, 7 figures, Latex. Lectures at the international workshop ``Brane world'' at YITP, 15--18 January 2002, to be published in Prog. Theor. Phys. Suppl. ptp style files included. v2: minor corrections, v3: minor corrections and refs. added, v4: eq.(7.14) correcte