Updated on 2022/05/20


TOMURA, Hajime
Faculty of Political Science and Economics, School of Political Science and Economics
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The current field of research is the institutional features of the financial system, such as currency, the payment system, and money creation, and financial crises. In addition to theoretical analysis that has been conducted so far, I aim to contribute to the improvement of the financial system in Japan by conducting relevant data analysis.


  • 2000.10

    London School of Economics and Political Science (Thesis title: "Economic analysis of the post-1990 stagnation in Japan.")   Ph.D. in Economics  

  • 1999.07

    London School of Economics and Political Science   MSc. in Economics  

  • 1994.04

    University of Tokyo   Bachelor of Laws  


  • 2006   University of London   Ph.D.

Research Experience

  • 2021.04

    Waseda University   Faculty of Political Science and Economics   Professor

  • 2015.09

    Waseda University   Faculty of Political Science and Economics   Associate Professor

  • 2014.04

    University of Tokyo   Graduate School of Economics   Lecturer

  • 2012.04

    Hokkaido University   Graduate School of Economics and Business Administration   Associate Professor

  • 2006.07

    Bank of Canada,   Senior Analyst


Research Areas

  • Money and finance   Financial system and institutions

Research Interests

  • Financial crisis

  • Money creation

  • Payment system

  • Currency


  • Associations between components of household expenditures and the rate of change in the number of new confirmed cases of COVID-19 in Japan: Time-series analysis

    Hajime Tomura

    PLOS ONE   17 ( 4 ) e0266963 - e0266963  2022.04  [Refereed]

     View Summary

    This study regresses the log difference over seven days in the number of new confirmed cases of COVID-19 in Japan on lagged values of household expenditures per household on eating out, traveling, admissions to entertainment facilities, clothing and footwear, and the other items, as well as a measure of mobility in public transportation in the past 14 days. The sample period of the dependent variable is set from March 1, 2020, to February 1, 2021, in order to avoid a possible structural break due to the spread of mutant strains in 2021. The regression model is estimated by the Bayesian method with a non-informative (improper) prior. The out-of-sample forecasts of the regression by the posterior means of regression coefficients perform well before the spread of the Delta variant in Japan since June 2021: R2 for the out-of-sample forecasts from February 2, 2021, to June 30, 2021, is 0.60. The estimated model is used to decompose fluctuations in the dependent variable into the contributions from each classified component of household expenditures.


  • Nominal contracts and the payment system

    Hajime Tomura

    The Japanese Economic Review    2020.07  [Refereed]

     View Summary

    A limited ability of the court to distinguish different qualities of goods of the same kind is introduced into an overlapping generations model. The model shows that fiat money recognizable by the court can circulate as both the means of debt repayments and the means of payments for goods endogenously. The model predicts that private money must be able to substitute the role of the civil court in contract enforcement, in order to replace legal currencies. The recipient of the 2021 JER Best Article Award.


  • Payment Instruments and Collateral in the Interbank Payment System

    Hajime Tomura

    Journal of Economic Theory   178   82 - 104  2018  [Refereed]

     View Summary

    The interbank payment system operated by the central bank can be characterized as a collateralized implicit interbank settlement contract to prevent a hold-up problem. This result explains the rate-of-return dominance puzzle on bank reserves.


  • Fiscal cost to exit quantitative easing: the case of Japan

    Hiroshi Fujiki, Hajime Tomura

    JAPAN AND THE WORLD ECONOMY   42   1 - 11  2017.06  [Refereed]

     View Summary

    This paper simulates the cash flows and balance sheet of the Bank of Japan (BoJ) before and after the end of Quantitative and Qualitative Monetary Easing (QQE) under various scenarios. The simulations show that the BoJ will record significant accounting losses after the end of QQE, because the yields on Japanese government bonds (JGBs) acquired during QQE will be lower than the interest rate on excess reserves after the end of QQE. These losses are fiscal costs for the consolidated Japanese government, as they correspond to increased interest expenses to the public. The extent of the BoJ's accounting losses depends crucially on the duration of QQE and the interest-rate elasticity of banknote demand. (C) 2017 The Authors. Published by Elsevier B.V.


  • Investment Horizon and Repo in the Over-the-Counter Market

    Hajime Tomura

    JOURNAL OF MONEY CREDIT AND BANKING   48 ( 1 ) 145 - 164  2016.02  [Refereed]

     View Summary

    This paper presents a three-period model featuring a short-term investor in the over-the-counter bond market. A short-term investor stores cash because of a need to pay cash at some future date. If a short-term investor buys bonds, then a deadline for retrieving cash lowers the resale price of bonds for the investor through bilateral bargaining in the bond market. Ex-ante, this hold-up problem explains the use of a repo by a short-term investor, the existence of a haircut, and the vulnerability of a repo market to counterparty risk. This result holds without any uncertainty about bond returns or asymmetric information.


  • Asset Illiquidity and Dynamic Bank Capital Requirements

    Hajime Tomura

    INTERNATIONAL JOURNAL OF CENTRAL BANKING   10 ( 3 ) 291 - 317  2014.09  [Refereed]

     View Summary

    This paper introduces banks into a dynamic stochastic general equilibrium model by featuring asymmetric information as the underlying friction for banking. Asymmetric information about asset qualities causes a lemons problem in the asset market. In this environment, banks can issue liquid liabilities by pooling illiquid assets contaminated by asymmetric information. The liquidity transformation by banks results in a minimum value of common equity that banks must issue to avoid a run. This value increases with downside risk to the asset price and the expected degree of asset illiquidity. It rises during a boom if productivity shocks cause the business cycle.

  • Heterogeneous beliefs and housing-market boom-bust cycles

    Hajime Tomura

    JOURNAL OF ECONOMIC DYNAMICS & CONTROL   37 ( 4 ) 735 - 755  2013.04  [Refereed]

     View Summary

    This paper presents a business cycle model capturing the stylized features of housing-market boom-bust cycles in developed countries. The model implies that over-optimism of mortgage borrowers generates housing-market boom-bust cycles, if mortgage borrowers are credit-constrained and savers do not share their optimism. This result holds without price stickiness. If price stickiness is introduced into the model, then the model replicates a low policy interest rate during a housing boom as an endogenous reaction to a low inflation rate, given a Taylor rule. Thus, monetary easing observed during housing booms are consistent with the presence of over-optimism causing boom-bust cycles. (c) 2012 Elsevier B.V. All rights reserved.


  • Asset illiquidity and market shutdowns in competitive equilibrium

    Hajime Tomura

    REVIEW OF ECONOMIC DYNAMICS   15 ( 3 ) 283 - 294  2012.07  [Refereed]

     View Summary

    This paper introduces asymmetric information in a competitive asset market into a dynamic general-equilibrium model with borrowing constraints. In the presence of borrowing constraints, asset sales become a crucial means for agents to finance opportunities to invest in new assets. In this environment, reduced asset sales due to asymmetric information lower the economic growth rate if agents invest in new assets. The volume of asset trade, however, becomes zero if and only if agents stop investing in new assets because of sufficiently low aggregate productivity. A low economic growth rate with a market shutdown is solely due to low aggregate productivity without any role of the market shutdown. Crown Copyright (C) 2012 Published by Elsevier Inc. All rights reserved.



    Hajime Tomura

    JAPANESE ECONOMIC REVIEW   63 ( 1 ) 104 - 130  2012.03  [Refereed]

     View Summary

    This paper presents a simple heterogeneous agent model to show that shocks that reduce aggregate borrowing capacity of producers under borrowing constraints cause endogenous productivity slowdowns through declines in asset prices and biased selections of producers. These dynamics of the model replicate the qualitative features of the Japanese economy during the 1990s, including a decline in the within effect in total factor productivity growth decomposition as well as default on mortgage loans. Policy experiments demonstrate that foreclosure restrictions already in place mitigate an exogenous productivity slowdown, but that a tightening of foreclosure restrictions causes an endogenous productivity slowdown.


  • International capital flows and expectation-driven boom-bust cycles in the housing market

    Hajime Tomura

    JOURNAL OF ECONOMIC DYNAMICS & CONTROL   34 ( 10 ) 1993 - 2009  2010.10  [Refereed]

     View Summary

    This paper analyzes the roles of credit market conditions in endogenous formation of housing-market boom-bust cycles in a business cycle model. When households are uncertain about the duration of a temporary high income growth period, expected future house prices rise during the high growth period and fall at the end of the period. But this development causes expectation-driven boom-bust cycles in current house prices only if the economy is open to international capital flows. It is also shown that high maximum loan-to-value ratios for residential mortgages per se do not cause boom-bust cycles without international capital flows in the model. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.


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Books and Other Publications

  • 全国銀行協会平成28年度金融調査研究会報告書 「新次元の金融政策のあり方」

    ( Part: Sole author, 第六章「マネーストックとノミナルアンカー」)

    全国銀行協会  2017.07


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  • The 2021 JER Best Article Award

    2022.01   Japanese Economic Review   Nominal contracts and the payment system

  • Waseda Teaching Award, The President Award

    2019.02   Waseda University   2017 Fall Semester

  • Waseda Teaching Award

    2017.02   Waseda University   2015 Fall Semester

Specific Research

  • 信用と保険に対する貨幣の補完機能に関する理論研究


     View Summary

    「信用が存在しうる環境でなぜ貨幣が必要になるのか」という研究課題については、「Nominal Contracts and the Payment System」という単著論文を書き上げ、査読付き国際学術雑誌であるInternational Journal of Central Bankingに投稿した。この論文では、貨幣を裁判所が認識できる債務返済手段(法貨)として位置づけ、その結果、貨幣が財市場での支払手段として使用され、また、日中当座貸越など、現在実際に行われている中央銀行による弾力的な貨幣供給が必要になることを理論モデルで導出した。介護のような社会保険支出の相互保険の機能を、法定通貨とは別の貨幣を社会に導入することで代替できるかについては、「Elderly Care and Multiple Monies」という早稲田大学現代政治経済研究所ワーキングペーパーの改訂作業を行った。

  • 決済システムにおける中央銀行の必要性の理論分析、そのマクロ経済学への含意の分析


     View Summary

    当該研究費により、東北大学で開かれた2015年日本金融学会秋季大会における非伝統的金融政策のセッションに出席した。その知見を活かし、日本銀行の「量的・質的金融緩和」が日本銀行のバランスシートに与える影響についての長期シミュレーションを行った。分析結果は2016年8月のNBER Japan Projectカンファレンスで報告される予定である。また、平行して、中央銀行が商業銀行に日中当座貸越をする必要があるようなlimited participationを標準的なマクロモデルである新古典派成長モデルに簡易な形で導入することに成功した。この結果は2016年4月東京大学でのマクロ経済学ワークショップで発表される予定である。



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Teaching Experience

  • ファイナンスの基礎(大学院、日本語)


  • マクロ経済学入門(学部、英語)


  • 金融経済学(大学院、日本語・英語)


  • 日本経済論(学部、英語)


  • ミクロ経済学入門(学部、英語)


  • 中級マクロ経済学(学部、英語)


  • マクロ経済学(大学院、英語)

    東京大学, 早稲田大学  

  • 国際経済学(学部、TAとしての補習授業担当、英語)

    London School of Economics  

  • 英語演習(学部、日本語)


  • 金融経済学(学部、日本語)


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Committee Memberships

  • 2016.06

    Financial Services Agency,  Payments Council on Financial Innovation

  • 2017.11

    Financial System Council,  Study Group on the Financial System

  • 2015.07

    Financial System Council,  Working Group on Payments and Transaction Banking

  • 2014.10

    Financial System Council,  Study Group on Payments and Transaction Banking