JaLCDOI 10.18926/OER/58075
FullText URL oer_051_2-3_123_129.pdf
Author Okamoto, Akira|
Publication Title Okayama Economic Review
Published Date 2020-03-19
Volume volume51
Issue issue2-3
Start Page 123
End Page 129
ISSN 2433-4146
language 英語
Copyright Holders Copyright © 2020 岡山大学経済学会
File Version publisher
JaLCDOI 10.18926/OER/41467
Title Alternative Income Distribution and Tax Reforms in Aging Japan
FullText URL oer_032_2_059_098.pdf
Author Okamoto, Akira|
Abstract This paper examines the effects of changes in the variance of income distribution on both capital accumulation and social welfare in Japan, the society with an aging population. To analyze the problem, we adopt a simulation approach for an extended life-cycle general equilibrium model of overlapping generations with continuous income distribution. The simulation results indicate that the changes in the variance affect economic variables under a progressive tax scheme but they do not under a proportional tax scheme. The results also show that social welfare greatly increases as the variance shrinks. Therefore, the recent shift in Japan, where the taxation system has tended in effect to become flat, may cause a significant damage to social welfare.
Publication Title 岡山大学経済学会雑誌
Published Date 2000-09-10
Volume volume32
Issue issue2
Start Page 59
End Page 98
ISSN 0386-3069
language 日本語
File Version publisher
NAID 110000130063
JaLCDOI 10.18926/OER/41456
Title Alternative Heterogeneous Labor Endowments and Tax Reforms in Aging Japan: Progressive Taxes and Intragenerational Redistribution
FullText URL oer_032_1_001_048.pdf
Author Okamoto, Akira|
Abstract This paper examines the effects of a progressive labor income tax scheme and a progressive consumption tax scheme on capital stock and on intragenerational wealth distribution in Japan, the society with an aging population. To analyze the problem, we adopt a simulation approach for an extended life-cycle general equilibrium model of overlapping generations. As a progressive tax is likely to mitigate the inequality of resource distribution, it is crucial to allow for the existence of heterogeneous labor. This is incorporated by assuming that each cohort has three representative individuals with equal tastes but unequal annual labor endowments, corresponding to three income classes, namely, low, middle, and high income classes. As the simulation results indicate, a progressive labor income tax shrinks the inequality in the distribution of wealth, while a progressive consumption tax furthers slightly.
Publication Title 岡山大学経済学会雑誌
Published Date 2000-06-10
Volume volume32
Issue issue1
Start Page 1
End Page 48
ISSN 0386-3069
language 日本語
File Version publisher
NAID 110000130040
JaLCDOI 10.18926/OER/40545
FullText URL oer_036_4_193_201.pdf
Author Okamoto, Akira|
Abstract With a population that is aging faster than any other in the world, Japan faces serious public finance problems, particularly when it comes to tax and social security issues. The structural reforms are urgently needed to accommodate the impending demographic change. We look at the Japanese tax and social security systems through a life−cycle general equilibrium simulation model. We aim to establish guidelines for fiscal reform in Japan’s graying society and use such advanced modeling techniques to permit the calculation of the effects of alternative tax policies on capital accumulation and economic welfare. We also examine the impact of progressive expenditure taxation, coming to the novel conclusion that this form of taxation may hold the key to overcoming the large welfare loss Japan faces as its society ages under the current tax system. Furthermore, we present the concrete measures of implementing progressive expenditure taxation.
Publication Title 岡山大学経済学会雑誌
Published Date 2005-03-10
Volume volume36
Issue issue4
Start Page 193
End Page 201
ISSN 0386-3069
Related Url http://www.e.okayama-u.ac.jp/gakkai/
language 英語
File Version publisher
NAID 120002576165
JaLCDOI 10.18926/AMO/32814
FullText URL fulltext.pdf
Author Okamoto, Akira| Yamamura, Masahiro| Iwahashi, Mitsuhiro| Aita, Tetsushi| Ueno, Akiko| Kawashima, Masanori| Yamana, Jiro| Kagawa, Hidetoshi| Makino, Hirofumi|
Abstract <p>High levels of soluble CD30 (sCD30) were detected in the serum and synovial fluid of patients with rheumatoid arthritis (RA), indicating the involvement of CD30+ T cells in the pathogenesis. We investigated the induction of CD30 and its functions in CD4+T cells from patients with established RA (disease duration &#62;_2 years). CD4+ T cells from both the peripheral blood (PB) and synovial tissue (ST) of RA patients expressed surface CD30 when stimulated with anti-CD3 antibody (Ab) and anti-CD28 Ab, but their CD30 induction was slower and weaker compared with PB CD4+ T cells of healthy controls (HC). Immunohistochemical analysis showed that only a small proportion of lymphocytes expressed CD30 in the ST (-1%). RA PB CD4+ T cells, after recovery from 6-day stimulation with anti-CD3 Ab and anti-CD28 Ab, showed in intracellular cytokine staining that CD30+ T cells could produce more interleukin-4 (IL-4) but less interferon-gamma. In the culture of RA PB CD4+ T Cells with anti-CD3 Ab and anti-CD28 Ab, blocking anti-CD30 Ab similarly inhibited the cell proliferation and activation of nuclear factor-kappaB on day 4 in RA and HC, but inhibited the apoptotic cell death on day 6 only in RA. These results indicate that despite high-level expression of sCD30, the anti-inflammatory activity of IL-4-producing CD30+ CD4+ T cells may be limited in the ST due to a poor induction of surface CD30 and a susceptibility to CD30-mediated cell death.</p>
Keywords apoptosis CD4 Tcells CD30 interleukin-4(IL=4) rheumatoid arthritis(RA)
Amo Type Article
Published Date 2003-12
Publication Title Acta Medica Okayama
Volume volume57
Issue issue6
Publisher Okayama University Medical School
Start Page 267
End Page 277
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 14726963
Web of Science KeyUT 000187556500001
Author Okamoto, Akira|
Published Date 2003-09-30
Publication Title
Content Type Thesis or Dissertation